I ran across this great little app today called HFS (HTTP file server) that allows you to very simply share any files on your system through HTTP. Yes, it's just a basic web server, sure it may not be super secure or anything, and yes it depends on your IP (can use dyndns or whatever you want though) and local outgoing bandwidth. But as far as ease of use and plug-and-play functionality, this is tops. I've definitely setup web servers on my system before and found some very good free apps to do this, but this one is really much more of a start-and-go solution for simple file sharing rather than a complete web serving solution, and as such it's the kind of thing you'd keep on a thumb drive or utilities disk. It's one of those "just works" apps and, considering its simplicity and ease of use, it's remarkably powerful.http://www.rejetto.com/hfs/?f=intro
It's not too big at 600kb, it requires no installation and it is incredibly easy to use. It starts out in easy mode and set to "On", so file sharing is immediately available. To share something just drag it into the HFS window. It operates on a "virtual file system", which is fairly flexible and cool. This allows you to create virtual folders to sort your shared files into, irrespective of what real folders the content might be sorted into. It also means you don't have to copy the data anywhere in particular or setup specific location links to anything to share a file. You just drag and drop, or right-click and choose Add Files or Add Folder From Disk. The virtual file system (VFS) can also optionally be saved to a file. This allows you to easily have multiple sets of different shared files/folders and switch easily and quickly between them. You can have the VFS saved automatically on exit and reloaded on startup. Once you have shared your files just select the file or directory you want to share in the tree view then copy the address shown at the top and send to whomever you want.
It's actually surprisingly powerful and configurable too, including options to change ports, throttle bandwidth and max users, ban people, etc. What's cool about it is that you don't *have* to mess with any of the powerful stuff to get it to work. You just start it and it's on. Share your files, send the address, and you're done. Couldn't be simpler really. They don't have to have an account with any website or have any special software, just a web browser. Of course it depends on your own outgoing bandwidth, but that's not too bad, especially to share smaller things.
Anyway, I'll stop gassing on. Again this is really nothing new, it's just well designed and setup.
Edit: The deeper I dig into this the more full-featured it seems. Which makes it all the more remarkable that it's so easy to use and setup. It has individual user/pass functionality for any file/folder, editable content presentation templates, display file in browser (MIME type support), logging, etc, etc. I dunno, maybe this will start a thread on good, free HTTP servers, but I've never found one easier or "lighter" (no install, etc.) that is also easy to use.