Pay for your hotel in Bulgaria (hey, everyone should visit it once...wait where the hell is it?)
http://www.motoroads.com/hotels/payp...on-payment.asp
Might have something here about paying for airfare with Paypal:
http://frequentflier.com/ffc-052103.htm
Type in hotels or airline tickets in the Paypal Shops search to find fights and hotels that accept Paypal payments.