You can get a .com for $3.99 a year using the coupon PPC399 and there doesn't seem to be any limit to it. My experience with them was ok at first, but I have to warn you their control panel is pretty confusing, so much in fact I accidentally deleted my account when trying to disable auto renew on my domain... When I did this I couldn't login, and no longer had access to my domain(didn't get a refund either), so I ended up calling and emailing them. It turns out this is a common problem, they told me they have thousands of domains just floating around in their system and they don't know who they belong to...I eventually got my account set back up, but the guy on the phone had to "trick the system" and it took a few more days. Needless to say i'm worried now to try and mess with anything...
If you google "cheap domain coupon" they're the 3rd down in the yellow box, can get a .com for $2.95 a year, if you need the exact URL let me know and i'll paste it here. This providers control panel is ok except editing WHOIS info is pretty annoying. Any edit you make is all encompassing for billing, technical, etc...contact info. Also their main "Edit Whois" button won't let you do what you want, you have to click My Contact Information link at the bottom of the page, to get to the guts of it. They also don't offer free email forwarding or anything else, so is bare bones unless you want to pay for extra stuff. Also the overwhelming upsell attempts everywhere in the panel is a tad annoying.
Hope this helps.