As for plants, Taste for Life magazine (available at health food stores and online at tasteforlife.com) has an article in the May 2007 issue about 2007 Herb of the Year: Lemon Balm. This herb has many, many uses, including repelling mosquitoes. Leaves rubbed on the skin will prevnt mosquitoes.

Also--not a plant but apparently non-oxic an effective mosquito repellent is now on the market (read about it in Real Simple magazine--June 2007, page 68) called Don't Bug Me (www.dontbugmepatch.com): "Vitamin B1 and aloe are released through the pores to deter bugs. It's non-toxic and waterproof, so there's no need to reapply after a dip." Testemonials on website sound convincing. I will be ordering a crate myself....