You might also want to check out IACE Travel at
IACE Travel USA (that's a link!). That's where I got my ticket for studying abroad last fall. It was *the cheapest* place I found (even cheaper than the travel agent at my mom's work could find!) It was a year ago, but I left in Sept and my ticket was a bit less than $1000 round trip, which is a really really good price to fly from the US. It was also for a seat on a NorthWest Airlines plane and I could have gotten tickets for United or other big airline companies, so it's not tickets to no name companies.
If anyone knows of better places (or good places from other countries), let us know!
Oh, and by the way, I don't suggest flying on your b-day... you'll just be in a plane your whole b-day and it will be the next day when you arrive. Won't it be more fun to spend your birthday with friends and family and *then* leave? Anyway, good luck on your travels!