http://www.freecondoms.com
I've tried it, and it works. It's a bit of a pain in the ass filling out the free samples, applications and all that... but for a few dollars (many of the good ones require a $1 registration fee) you can get a 500 pack of any type of condom you like. Or you can get sampler packs. You can even get lube.
Last I checked, they're Durex condoms, which are some of my favorites. Enjoy.
Edit: I decided to explain the site.
Basically what you do is sign up for an account, which is free. You then sign up for advertising partners' free trial periods, which gives you points. You then redeem your points for condoms. Simple.
Example: I sign up on freecondoms.com as CondomNeeder. I register for the AOL for Broadband free trial. Sometime that day (how long depends on WHICH free trial you get) I get 700 points added to my freecondoms.com account. I then unsubscribe from AOL,* and there's no charge to my credit card. I then redeem 300 of those condom points for a 30 pack of any type of condom I like. If you subscribe to multiple free trials, you can accumulate points. If you get 3000 points (not hard if you get the big ones), you can get a 500 pack of 1 type of condom. Neat, huh?
*Just a note: When you're unsubscribing from free trials, you have to make sure to be FIRM with the people. It took my friend half an hour on the phone with the AOL person to get them to delete her account. I told them "There's no way you can convince me to keep the account, or to get a different type. Cancel my account or give me to your supervisor." I got it cancelled in 30 seconds flat.