Several of the "How to Root" articles that I've shared with you recently have a prerequisite of being "temprooted" — have temporary root permissions. Temproot, unlike actual root or "permaroot", is lost when you restart your phone. However, while you're temprooted you can do all sorts of stuff that requires root permissions, such as applying various modules and instructions to enable permanent root.
VISIONary is the app that I've referred to in these articles as the app to use to get that "temproot" on your phone. Available from the Android Market, easy to install, easy to run, and able to be set to run at boot, VISIONary is great. Apparently it was a little too great — and has subsequently been removed from the Market.
But, as with most things of this nature, developers will find a way... and that way is simply distributing the .apk directly via the MoDaCo forum.
So, if you're trying to VISIONary temproot your device, and can't find it in the Market, download the app from here and you're all set!