I Just read this on the daily WTF (which got renamed to Worse Than Failure the other day)
An insurance company decides to install the trial version of SQL server 2000 on their production box because they don't want to pay the license. After 6 months they backup all the data, wipe out the hard drive (reimage) and install the trial version again, restore all the databases and are good to go for another 6 months...ROFL
Why not just use developer edition? You are violating the license anyway, it will at least save you the hassle of reinstalling every 6 months...
Link to original article is here http://worsethanfailure.com/Articles/SQL_on_Trial.aspx