One of the major bucket list websites out there is ReaperList.com. The website's tag line says it all: Check it out before you check out!
Reaper List is a social site for folks who want to create and share their own personal bucket lists - the things that they want to do before they die. As of December 2010, the site has almost 2,500 users, where individuals have created lists of around 30 items. The site will let you build longer lists if you need to.
What I like the best is their monthly email newsletter, which acts like a friendly reminder to update their lists and keep Reaper List top of mind. Each newsletter highlights a list of the month, and in true social fashion, invites subscribers to nominate one of their favorite lists.
It's easy to get started. All you need to do is set up an account. Check it out at ReaperList.com.