When we started my current company we decided we wanted our project names to have a theme. After casting around for a bit we decided on rock bands. We figured this had many advantages:
1. A near-endless well of distinctive names, such that each major release could get its own band.
2. We could assign different sub-genres to different products. The mapping product would get classic rock, the mobile viewer gets blues-rock, the design product get metal bands (for reasons simply related to the tastes of the personnel involved).
3. For point releases we could use band member last names. Our 2.0 mapping product project was Zeppelin, 2.1 was Plant, 2.2 was Page, etc.
The runner-up theme was "battles the French lost" but it only had the "near-endless well of names" factor going for it ;)