Hey
Just to clarify the "hidden" link thing ...a hidden link is not a backlink that is somehow disquised (and thus valueless) but a way for traders to add domains they only want to trade to, not from. Thats quite a normal practice and nothing shady, for instance most people dont want outgoing links on paysites/affiliate entry points - but they still want trades to them, which isnt a problem - as long as there are other backlinks to choose from of sufficient quality.
Most traders dont linktrade directly back and forth - but do A-B-C or A-B-C-D...so if say you get a link request for your a link on your site
www.tadpole.com to a site called
www.hincapie.com - then you go and see what you can get in return, you dont see
www.hincapie.com as its hidden (but if it wasnt, you would be a bit silly to choose it anyway, as it would largely ruin the value of the trade, as it would be a plain recip trade - if you want the link back to
www.tadpole.com that is).
So, instead you figure you want a link on
www.kinkybob.com, you add that to the request and ask for a link back to
www.tadpole.com or one of your other sites. You get a nice link kinkybob.com, i get a nice link from tadpole.com - everyone is happy...