For cheap and visible, O2 rain gear is hard to beat: http://www.outsideoutfitters.com/p-1...FUVk7Aod1D0A4w

Also they pack up small. Not the greatest thing in the world but will keep you dry and won't make you broke. If you find that you want something a little nicer, I wear an eVent waterproof jacket that I got on http://www.geartrade.com for something like $50 - it's a good place for deals. Also for a Chicagoan it can't hurt to check out http://www.thechainlink.org and ask the locals for tips on all-season commuting. Good luck!