If you need a simple one, do have a look at this:
http://www.rejetto.com/hfs/QUOTE
What is it?
... it's file sharing
... it's webserver
... it's open source
... it's free
... it's guaranteed to contain no malware
Features
Download and upload
Virtual file system
Highly customizable
HTML template
Bandwidth control
Easy/Expert mode
Log
Full control over connections
Accounts
Dynamic DNS updater
You like this software?
I like donations!
Consider even 3$
Description
You can use HFS (Http File Server) to send and receive files.
It's different from classic file sharing because it uses web technology
to be more compatible with today's Internet.
It also differs from classic web servers because it's very easy to use and runs "right out-of-the box".
jaclaz