I know how you feel about the jummy wool we can't use, but there are some alternatives. The best one is cascade fixations, or elann.com esprit. You can knit them with 3mm needles, which is a bit larger than usual. I've tried 2.5 mm (ususal size), but that didn't work. I can hardly get the socks on my feet, the fabric is to sturdy.
If you like the nice selfpatterning yarns you can get with wool: it excists in cotton now. Unfortunately, it has only been made in the summer of 2007, so you have to buy it quickly, it has already been discontinued. I've found an online shop in the us which has it: click herebut it's rather expensive in the US. I think if you want more than one ball, you'd better order it in Germany: Mariannes opalwolle. They've also got another woolfree sockyarn: Flotte socke Baumwolle
Last thing I can recommend you is Grumperina's list of woolfree sockyarn
If you want more information, or need some help with your German, you can always pm me.
ETA: I've found less expensive sockina cotton summer dream on ebay: Autum colors (I'm knitting with them); stone colors; wine and Schilf (can't find a proper english translation for that one)