Thankfully for those pressed for time, several key streets offer some (or even all) of London's best retail stores, compactly located in a niche or neighborhood so you can just stroll and shop.

GST: Greenwich Shopping Time--Though many London shops are now open on Sundays, the best Sunday shopping is in the stalls of the flea and craft markets in the royal city of Greenwich.

The best way to enjoy the trip is to float downstream on a boat from Charing Cross or Westminster pier (service begins at 10:30am on Sun.) The trip takes about a half-hour, but you'll get a knowledgeable commentary on the Docklands development and the history of the river, and view the Tower and much of London from the water along the way.

The boat leaves you in the heart of Greenwich, minutes from the craft market held on Saturday and Sunday. Follow the signs--or the crowd. After you're done, follow the crowd again to Greenwich's several antiques markets. First is Canopy Market, which isn't under a canopy at all, but sprawls through several parking lots where junk and old books abound, and then onto High Street, where the fancier flea market is held. It's possible that there's yet another antiques market at Town Hall, across the street, but these shows usually charge an admission fee.

You're only a half block from the Greenwich BritRail station now, which is on Greenwich High Road; and there's a train back to London every half-hour, until about 11:30pm.

- Kensington, Notting Hill & Bayswater
Kensington High Street (Tube: High Street Kensington) is the hangout of the classier breed of teen, one who has graduated from Carnaby Street and is ready for street chic. While there are a few staples of basic British fashion here, most of the stores feature items that stretch, are very, very short, very, very tight, and very, very black.

From Kensington High Street, you can walk up Kensington Church Street, which, like Portobello Road, is one of the city's main shopping avenues for antiques, selling everything from antique furniture to Impressionist paintings.

Kensington Church Street dead-ends at the Notting Hill Gate Tube station, jumping-off point for Portobello Road; the antiques dealers and weekend market are 2 blocks beyond.

Not far from Notting Hill Gate is Whiteleys of Bayswater, Queensway, W2 (tel. 020/7229-8844; Tube: Bayswater or Queensway), an Edwardian mall whose chief tenant is Marks & Spencer. Whiteleys also contains 75 to 85 shops, mostly specialty outlets and restaurants, cafes, and bars as well as an eight-screen movie theater.

- Knightsbridge & Chelsea
Knightsbridge (Tube: Knightsbridge), the home of Harrods, is the second-most famous London retail district. (Oxford Street edges it out.) Nearby Sloane Street is chock-a-block with designer shops.

Walk southwest on Brompton Road (toward the Victoria and Albert Museum) and you'll find Cheval Place, lined with designer resale shops, and Beauchamp (Bee-cham) Place. It's only a block long, but it's very "Sloane Ranger" or "Sloanie" (as the Brits would say), featuring the kinds of shops where young British aristocrats buy their clothing for the "season".

If you walk farther along Brompton Road, you connect to Brompton Cross, another hip area for designer shops made popular when Michelin House was rehabbed by Sir Terence Conran, becoming the Conran Shop. Seek out Walton Street, a tiny snake of a street running from Brompton Cross back toward the museums. Most of the shops along this street specialize in non-essential luxury products, the kind a severe and judgmental Victorian moralist might dismiss as vanities and fripperies. This is where you'll find aromatherapy from Jo Malone, needlepoint, or costume jewelry. King's Road (Tube: Sloane Square), the main street of Chelsea, will forever remain a symbol of the Swinging [']60s. It's still popular with the young crowd, but there are fewer mohawk haircuts, Bovver boots, and Edwardian ball gowns than before. More and more, King's Road is a lineup of markets and "multi-stores," conglomerations of indoor stands, stalls, and booths within one building or enclosure. About a third of King's Road is devoted to "multi-store" antiques markets; another third houses design-trade showrooms and stores of household wares; and the remaining third is faithful to the area's teenybopper roots.

Finally, don't forget all those museums in nearby South Kensington--they all have great gift shops.

- The West End
As a neighborhood, the West End includes Mayfair and is home to the core of London's big-name shopping. Most of the department stores, designer shops, and multiples (chain stores) have their flagships in this area.

The key streets are Oxford Street (in either direction) for affordable shopping (start at Marble Arch Tube station if you're ambitious, or Bond Street station if you only care to see some of it), and Regent Street, which intersects Oxford Street at Oxford Circus (Tube: Oxford Circus). The Oxford Street flagship (at Marble Arch) of the private-label department store Marks & Spencer ("Marks & Sparks" in the local parlance) is worth visiting for quality goods. Regent Street, which leads all the way to Piccadilly, has more upscale department stores (including the famed Liberty of London), chains (Laura Ashley), and specialty dealers.

Parallel to Regent Street, Bond Street (Tube: Bond Street) connects Piccadilly with Oxford Street and is synonymous with the luxury trade. Divided into New and Old, it has experienced a recent revival and is the hot address for international designers; Donna Karan has two shops here. A slew of international hotshots, from Chanel to Ferragamo to Versace, have digs nearby.

Burlington Arcade (Tube: Piccadilly Circus), the famous glass-roofed, Regency-style passage leading off Piccadilly, looks like a period exhibition and is lined with intriguing shops and boutiques. Lit by wrought-iron lamps and decorated with clusters of ferns and flowers, its small, smart stores specialize in fashion, jewelry, Irish linen, cashmere, and more. If you linger there until 5:30pm, you can watch the beadles (the last London representatives of Britain's oldest police force), in their black-and-yellow livery and top hats, ceremoniously place the iron grills that block off the arcade until 9am, at which time they just as ceremoniously remove them to start a new business day. (There are only 3 beadles remaining.) Also at 5:30pm, a hand bell called the Burlington Bell is sounded, signaling the end of trading.

For a total contrast, check out Jermyn Street (Tube: Piccadilly Circus), on the far side of Piccadilly, a tiny 2-block-long street devoted to high-end men's haberdashers and toiletries shops; many have been doing business for centuries. Several hold royal warrants, including Turnbull & Asser, where HRH Prince Charles has his P.J.s made. A bit to the northwest, Savile Row (between Regent Street and New Bond Street) is synonymous with the finest in men's tailoring.

The West End theater district borders two more shopping areas: the still-not-ready-for-prime-time Soho (Tube: Tottenham Court Road), where the sex shops are slowly converting into cutting-edge designer shops, and Covent Garden (Tube: Covent Garden), a shopping masterpiece unto itself. The original Covent Garden marketplace has overflowed its boundaries and eaten up the surrounding neighborhood; it's fun to wander the narrow streets and shop. Covent Garden is mobbed on Sundays.

Just a stone's throw from Covent Garden, Monmouth Street is somewhat of a London shopping secret: Londoners know they can find an array of stores in a space of only 2 blocks. Many shops here are outlets for British designers such as Alexander Campbell, who specializes in outfits made of wispy materials. Some shops along this street specialize in both used and new clothing. Besides clothing, stores specialize in everything from musical instruments from the Far East to palm and crystal ball readings.