However, you can probably go thru anonymizer.com and use the free tool bar at the top of the page to browse. I only mention it because you can't post or do anything nefarious thru it but browse a few pages.
Otherwise, get a new IP - unless they blocked a range then you're screwed unless you get a new ISP or connect from a web cafe or something...
Your IP is usually blocked for a reason.
I wouldn't be comfortable giving you a method to bypass it unless you are willing to provide more information. Sounds far too suspicious especially from a new user.
Sites which block your IP may also refuse anonymous proxy IP addresses as well. Personally, I always advise forum admins for popular forums to block hundreds of well known anonymous proxy subnets (and/or write scripts to check against proxy rbls at signup) to stop aliasers from bypassing IP bans.