Best/Easiest way to change IPs on a Mac

I've been led to believe that most of the IP-switching software out there is for PCs. Well, I'm on a Mac, and I need -like you all- to be able to change my IP in order to access eBay/PayPal time and time again for different accounts.

Could anyone supply me with some savvy methods of doing so? I've found IP lists online and I've been attempting to use FoxyProxy (Firefox app) to apply them manually, but it seems like only 1 out of every 30 seems to work, and when it does, it works slowly and not quite all that efficiently.

Just wondering/hoping for your savvy input on this matter. Although I know it is the stablest way to secure an IP - and I apologize for being picky, I would like to place the option to pay for IPs as the very last resort.

Thanks.

Change IP: http://www.proxy.org

Change MAC adress: http://www.versiontracker.com/dyn/moreinfo/macosx/33101

Well, maybe it's not what exactly you ment (because my solution is so simple) but did you tried using just different browser?

It works pretty well for me, just everyday I use 3 different ones at THE SAME time, browsing andusing different accounts THE SAME time; without changing or masking any ID etc. Sometimes I clear cookies,ok. That's all.

Too simple? Or not the solution to your problem?

Even with a different browser, the Computer's IP address is still the same, right? And that's what they catch.

I'll see what proxydotorg and the other link are about- thanks for the responses, both of you.