I finally got to check out the "slides" at the The Unilever Series: Carsten Höller at the Tate Modern in London, England so if you are in the city before April 9th 2007, definitely check it out.
You can slide down the Level 2 slides for free (though mostly for kids) but Level 3,4 and 5 need tickets that are available free from the ground level ticket booth but have a time reservation on them (with a 30 minute time chunk to work with). (Though it was busy from the kids on holiday the day I went, by 11:30 am, they were already handing out 3pm tickets for Level 5 so arrive accordingly). Level 4 and 5 are definitely a lot of fun and faster and more dizzying than you would think.
I also checked out Caroline, Or Change The Musical at the National Theatre (which has since closed) but found it was better when thinking about the show than actually watching the show. (Chandra Wilson, Bailey on Grey's Anatomy was in the original Off-Broadway production back in 2003) Tonya Pinkins starred as Caroline, reprising her role from Broadway and was great, but the whole thing felt like it was trying too hard to be important while being small and quaint and I could appreciate it more than I loved or enjoyed it. The musical was about a black maid for a Jewish family in 1963 Louisiana, and basically deals with the Jewish boy who must choose between his devotion to Caroline or a cup of change leftover from the pockets of shirts in the laundry. The title is more brilliant than the actual musical.