When someone clicks on a 'magnet' link, LimeWire will send a query into the Gnutella network to download a file. The magnet links can also have an 'anchor' location that LimeWire will always attempt to retrieve the file from. In the future, things such as an 'email this file to a person' may exist, which would generate a magnet link in an email, so that the other person can retrieve the file at their convenience, instead having to clog up their email boxes with files. That particular usage would be a change from a 'push' to a 'pull' kind of model for email -- and it might be pretty neat.

Other uses for magnet links are to spread out the bandwidth consumption from downloading files -- for instance, if I wanted to share pictures from a trip I took to Italy this past winter, I could generate a webpage with magnet links to those files. People would click on them and the files would be retrieved from any computer on the network that has downloaded the files -- and could also be anchored at my computer's location, just to guarantee they get them from some source. This is particularly useful because my website provider doesn't have the space for every site to store large amounts of data (approximately 194 MBs for my pictures alone).

A magnet link looks like an http link, but begins with the 'magnet:' instead of 'http:', and contains some specific information that LimeWire uses to send the query to the network or begin downloading a file.

There's no direct way to generate links for files yet, but that may come along soon.