If you are a fan of Rezzable here's another sim to add to your collection: Mars Areas01 Rezzable. I am not sure if it's officially open yet, but there seems to be a fair amount of traffic already. This sim, like a number of others in the Rezzable family, seems to be best described as an art installation. You arrive in a vast space, filled with translucent balls that gradually change colour as you watch. Bursts of plasma (or something) zip between the balls (ooh, sounds painful). A teleport lifts you to a big tubular affair that seems to serve no purpose other than to be a big tubular affair. And there's some stuff you can discover, like the "space seats" illustrated below.
Aside from that, there's not a lot else I can tell you. It's cleverly done - but left me feeling a bit "so-what-ish." God, what a jaded palate I must have. Anyway, despite this rather lacklustre report of mine, I would urge you to pop along and form your own opinion. For those who can't make it, won't make it or simply want a quick look-see, here are some pictures:
Finally, thank-you to my top informer - you know who you are - for tipping me off to this build.
UPDATE: Lem informs me (see comments) that this is something of a "hack" build, done in a short space of time, and could be zapped at any time. So if you want to check it out, you better get your teleporting skates on.
UPDATE 2 on 21-10-07: There is a more on this at Not Possible IRL.