There are plenty of sites that allow you to upload a file and share it via a link but not many are suitable for use here.
Most of them offer a free service but have a file expiry time of 90 days or other similar restrictions.
I have looked at mediafire, box.net, snap drive, and keepandshare.com
KeepAndShare seems ok - signup is not too onerous and its fairly easy to use. Files appear to be permanent and the only thing you need to do to keep it alive is to log in once a year.
I have posted a very simple file just as a test and it should be available here -
test.xls
KeepAndShare gives you a choice of 3 different links you can use - this was done with the "immediate download" one
The link in this message was inserted using the icon to the right of "insert picture" when making a post.
edit - it works for me if I am logged in - does it work for anybody else ?
Mick