If you have an Ebay account, you can qualify for a free Stamps.com account. It enables you to ship packages (including international), but because it is intended for those types of uses it does not include letter rates or the other range of services a full-pay account might include.

Using cut and paste, I am able to use Stamps.com for my PayPal orders to take advantage of first class international rates (which PayPal does not offer). I can also create non-Ebay orders when sending to friends, family, etc. - and can save their addresses in the address book for convenient use later (something PayPal doesn't offer).

This is not a limited time offer; I have had my account for more than a year. It does offer the limited scope noted above, though (namely, it's for packages, not letters).