PokerStars just added a trial super turbo (called hyper turbo) at the lower levels (see the PokerStars structure changes news post for more info there).The Merge network also has super turbos, but they start with 1500 chips and 25-50 blinds (30 effective big blinds versus Full Tilt's 25).  They get shorter stacked faster than FTP's structure, however, as the blinds double (FTP's gradually increase).iPoker network also has some super turbos, as does another non US network (ongame or microgaming I believe I forget which one).  I believe iPoker's super turbos do something a bit silly like start at 1500 chips and 10-20 blinds and increase levels every 1 minute or so (that could be inaccurate though, somebody confirm/deny please).  And the other euro network I believe had a very short stacked structure, likely unbeatable without 75% rakeback and good skills.So the best places to play super turbos would likely be Full Tilt, Merge Network and PokerStars, with a possibility of iPoker (but their structure is much different).

Cake has some super turbos as well I believe, but I think the structure is too rake heavy and/or too short.