Lately a lot of users are linking to some images from my server, generating more traffic to my server.

I run IIS and I don't know if there's a way of stoping this? A program, script or something?

If I can pick, is there one free?

http://coldlink.com/ is one, although not free.

Leech Blocker and it works and is free!

http://www.michaelbrumm.com/leechblocker.html

Thanks I'll try it

Hi,

I thought I'd just stumble in here and mention that
leechblocker uses the http-referer header only, while
coldlink ignores http-referer in favour of expiring
cryptgraphic keys.

This hotlinking prevention article explains why the difference might be important.

You also might want to check out this online anti-hotlinking test tool

cheers!

I have been using leechblocker .. its nice..

I think this one is better, especially if you have multiple virtual web sites. Supports individual configuration file for each web site.
Looks like a good replacement for good .htaccess from linux

http://www.isapirewrite.com/docs/