A Python script that works recursively through the directory its in, listing all of the contents into a text file, ready for folded-up Vim viewing.
Can easily handle large numbers of files (my biggest yet is 880,000, generating a 252,000 line file, but nicely folded up and easily searchable in gVim).
To get the full benefit - folded and syntax highlighted in gVim - you will need in your installation of gVim:
The unix command
ls -R1 also produces a nicely formatted listing, but it would need post-processing to compact it down, and is less convenient, of course, to access in Windows 7.