What's the Best Free Helpdesk Software that Integrates?

I was looking at PerlDesk (any opinions?) but it would cost $90 with the plugin and lisence.

Are there any free alternatives that integrate easily with aMember so that user's don't have to have double logins?

Thanks

Just check out aj help desk at http://www.ajsquare.com/products/helpdesk-software/index.php . I suggest that this is the best help desk software.

I use Trellis (free) and Jlogica's plugin (cheap)

Works beautifully.