Radmin and PC Anywhere are remote control programs, although file sharing is also possible with such apps, I don't think Nathan is looking for that.
Apache will allow him to share files over HTTP connections so his friends can easily download his files without having to install client software or using dodgy java applets to connect.
There are simpler/ligther HTTP servers availible if you just want it for filesharing though (if you won't need any fancy things like php, mod_rewrite and dozens of modules). I think there was a good alternative on Segosa's blog once, let me search
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EDIT: Here it is:
http://m00.cx/comments.php?pid=73
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