Claritin (Loratadine is the generic name) would be your best bet - it's available without a prescription and you can get the generic pretty inexpensively. It's a non-drowsy antihistamine and works for 24 hours at a time so you only have to take it once daily. Another option in 2008 will be Zyrtec (Cetirizine) which will be available without a prescription after the first of the year (but will probably be pretty expensive at first).

I'd start with generic Claritin and see how that works for you.