Tiny Tower: Now at 60 floors with 110 bitizens and 106 dream jobs. Tip for more dream jobs...occasionally stop ordering and go into an eviction frenzy, then use accumulated towerbux to move in bitizens. The higher the tower, the more likely a bitizen matches a store. Often, when a biz has three happy bitizens, then give one of them a temp job in order to hire the new lesser skilled only to cash in on the 3 towerbux reward, then evict. In the end, you end up with more towerbux than spent and lots of happy bitizens. It's almost another game within the game.

Helpful sites:
Tiny Tower Wiki
Tiny Tower Guide
Tips & Strategies Thread on TouchArcade

Update note: uh oh...the new 1.2 release only rewards 1 towerbux for placing a dream job. This effectively eliminates the sub-game of moving people in to dream jobs for big towerbux gain. An alternative sub-game: evict everyone from the building and earn towerbux as new bitizens move into dream jobs.