A similar topic came up on this earlier. Unfortunately, Lamia is a decidedly low pop server averaging around 7,000 players. To be fair, if you've only just reached Foundation, it isn't going to too populated on most servers because plenty have reached Idyllshire. That being said, you'll find more than double the playerbase on Gilgamesh or Balmung. I have a friend who actually transferred from Lamia to Balmung and he's talked about how it feels like a different game. Food for thought on both servers:

- Gilgamesh is the unofficial raid server and generally more endgame focused.
- Balmung is the unofficial roleplay server, though it has seen a growing raid focus, albeit in a more casual scene.

Both are in the Aether Datacenter, so when the cross server party finder comes out in 3.5, groups can be setup regardless of the server you're on. I can't speak too much for Greg, but Balmung is very populated in major cities like Ul'Dah and Limsa.