Blockland is a really cool online game that Brophy recently introduced us to. It's basically multiplayer lego, and can be a great laugh.
Some screenshots:
Blockland can be downloaded here.
A few of people from this forum/MTA IRC play it: XcR, MAD_BOY, MrBump, BrophY, Gamefreek and Mike. If you would like to play come on IRC and set up a game
Picture of a skyscraper:
Overall this is a fun game and definately worth downloading to try. The filesize is 8.9mb, so any connection can handle it.