How about Africa? I'm considering going there sometime in 2008, and have received some fantastic advice from fellow Flyertalkers! ^
Your budget, however, may make it difficult, as I don't think there are a lot of cheap tix between N.Am. and Africa.

In terms of Europe, you could do IST and the Eastern Balkans (Bulgaria, Romania) for not a lot of money...Great combination of natural beauty, urban life and the occasional bits of culture. I wouldn't spend more than a couple of days in Malaga, but Andalucía is a great place and distances are quite small, so you can hire a car and go to SVQ, GRX, ODB, GIB and Cadiz without spending too much time on the road.