I was listening listening to one of the old Geek Brief podcasts, and was reminded of a website with portable versions of applications that are very useful when supporting computers that aren't your own, or running from several different PCs.
Of particular note are the Development apps available.
Notepad++ is an excellent text editor based on the SciTE editor that comes with Ruby installations. It's not quite my old standby gvim, but then again, it doesn't need much customization to do its thing either.
Also included in the section is XAMPP, which includes Apache, mySQL, PHP and Perl. In addition, the FULL version package includes valuable extras like phpMyAdmin. I haven't experimented with either the lite or full package, but I will be reloading a PC soon, so I'll see then how much more smoothly this package makes setup for me.