Does Blockbuster or any chains you know of rent systems? I used to get coupons in GamePro back in the day to rent PlayStation, did that a couple of times...I only ask b/c I'd love to try out Wii before diving in...
If not, then you could always track down a GS/EB kiosk. Yeah, it won't be the best experience, but at least you'll have SOME experience to go off of when deciding whether to get one.
Way back in the day I used to work there when I was still in HS. I remember those damn systems always getting stolen. Crap was always busted and they wanted a hefty deposit. We used to keep all the games in drawers behind the counter... man it used to suck to have to search for a game someone misplaced. I remember when we got the virtual boy in the store... man that was terrible lol.