On the p1k3 wiki, you can easily link to other sites using the intermap feature, like this:

* MeatBall:InterWiki
* UseMod:InterMap

* Brent:UltimateCreativitySpace
* Daemonsong:Eschatology
* Wikipedia:Yerba_mate
* P1k3:wiki_software_notes

Handy if your friends are also running a wiki somewhere.

(Does not actually work right now. May implement.)