San Francisco: Decoding the new Clipper pass

Attention, American visitors to London who are paying high prices to see Andrew Lloyd Webber musicals in the large West End theaters: Are you crazy? The locals are far more excited about pop-up theater performances all over town. Abandoned warehouses and after hours subway stations now double as stages. Shows are inventive and inexpensive. The trend began a year ago, when Kevin Spacey, who runs the city's Old Vic Theatre, discovered spooky tunnels under Waterloo subway station. He organized a spontaneous series of stage performances there by the theater group Punchdrunk. The shows were a hit, and it became cool to think outside the black box. This summer, Spacey and his Old Vic colleagues created a 160-seat theater in the tunnel, with Art Deco cinema seats and The Bunker bar. Visiting in December? Book now to see a tunnel staging of Cart Macabre, a co-production by Old Vic and Living Structures. It's been described as "a restless exploration of isolation and disorientation, an act of faith on the part of the audience." I admit that sounds a little weird. But tickets are only 14 pounds each! And think of the stories you'll have to tell when you get back home. (December 4 to 22, livingstructures.co.uk and oldvictheatre.com.) Pop-up theater performances won't have a familiar Phantom score, but don't let that weaken your resolve to try something new during your vacation. MORE LONDON POP-UP THEATER… Fly Theatre is reviving the workplace satire Contractions in an empty office complex in the prime shopping district of Oxford Street. Audience is limited in size to 40 people for each performance of the comedy, a kind of twist on The Office. 26-30 October 2010. contractionsplc.co.uk, £9. Theatre Souk performs in an abandoned building off the popular Bond Street. Through Friday Oct. 16, it's hosting a set of performances. Future line-up of shows to be announced soon. theatredelicatessen.co.uk, £7 INSIDER TIP: To hear about future shows in the Old Vic Tunnels, fire off an email to oldvictunnels@oldvictheatre.com with "mailing list" in the subject line. LODGING: Find affordable and stylish places to stay in Budget Travel's easy-search London hotel database.

Unlike celebrity-studded fests in Venice and Cannes, the International Rome Film Festival, which runs from October 28 to November 5, is a laid-back affair that's accessible to both locals and English-speaking visitors. You're more likely to see Romans munching on pizza outside one of the theaters than Angelina Jolie in oversized designer sunglasses. The fifth annual festival presents a diverse lineup of films such as Last Night directed and written by Massy Tadjedin and staring Keira Knightley and Eva Mendes; Rabbit Hole, Nicole Kidman's debut as producer, starring Kidman and Aaron Eckhart; and Oranges and Sunshine by Jim Loach. There is also the opportunity to watch Anita Ekberg splash around the Trevi Fountain on the big screen—a restored version of Federico Fellini's iconic film La Dolce Vita will be screened in honor of its 50 anniversary. Auditorium Parco della Musica—designed by world-famous architect Renzo Piano— is the primary event host and has on-site restaurants and gift shops. Tickets are priced from €3 ($4.15) to €23 ($32) and go on sale October 12. If you show up at the box office with a ticket from one of Rome's museum, you get a 10 percent discount. Get ticket details at romacinemafest.it. PREVIOUSLY A wry film from a Roman mama's boy

I'm not aware of ever having attained inner peace. But on Thursday I came close to doing so while viewing the four oversize, curving sculptures that for the past week or so have been drawing visitors to London's Kensington Gardens. The city's star artist, Anish Kapoor, has made the mirroresque artworks specifically for this royal corner of Hyde Park, with its sightlines pleasantly free of any skyscrapers. Kapoor is famous in the U.S. for his so-called "millennium bean," a glinting installation near Chicago's Grant Park. He cribbed that same "reflective object outdoors" concept for dreaming up these sculptures that he's put in the city's most central park. One of them is a curved reddish disk floating on a lake and reflecting the landscape, a bit like the famous painting within a painting by Rene Magritte. Another is bent like a funhouse mirror. A third is conical, like an upside down tornado. The most popular of the sculptures looks like a satellite dish large enough to contact Saturn. The mirror brings a reflection of the sky down to earth, placing an image of the clouds upside down and next to a lake that's home to several mute swans. Stare at the sculptures for a while, and you'll be surprised at the memories or ideas that pop into your head. I found myself thinking that the sculptures looked like sinister objects from outer space. Maybe they will one day play a frightening chord, like those shiny monoliths in 2001. But this installation is about inner peace. Hard for me to find, like I said. Go and find the giant mirrors and your own center of calm before March 13, when they come down (kapoorinkensington.org.uk, free).

San Francisco's annual Fleet Week, starts this Thursday, so don't be surprised if you see fighter jets flying overhead or a general roar coming from the sky. During Fleet Week, the Blue Angels of the U.S. Navy and other pilots will be performing daring acrobatic air shows in the skies over the city. You can catch a glimpse from pretty much anywhere in San Francisco, but for ideal views of the air show, head down to waterfront near Pier 39 and the Marina Green between 1 and 4 p.m. on Saturday or Sunday. Reserved seating is also available, from $25. Military vessels will also be open for public viewing over the weekend, including the massive USS Pinckney, a guided-missile destroyer on Pier 35. The Canadian Navy will also have ships participating, for good reason—2010 marks their 100th anniversary. October 7-12, dates and times vary. See full schedule here.