Textlinkexchange
A discreet but effective alternative of advertisement.
Here no banners or sites are exchanged, but only textlinks.
Textlinks are relatively inconspicuous, but they are very popular and have a high klickratio.
The users can insert the textlinks into their site-navigation, without changing the appearence of their website.
With the use of stylesheets the textlinks can easily be integrated into the website.
So it is especially nice and simple possible to insert several textlinks without the website seeming to be to overcrowded.