Check the forsale forum... someone else just posted the same question over the weekend. More info there, but here is the basics:
Just call your local glass shop. Around here it was about $43 plus sales tax. Here's (almost) exactly what to ask for:
1/4"
Clear
Tempered
22"x32"
4 corner radius cuts
Sanded (frosted or polished) edges
No bevel
The only thing I don't have in the list is the EXACT radius of the corner cuts... the other thread I think has it)
Also if you search eBay there is someone who is *constantly* listing it for $70 which INCLUDES FedEx ground shipping in that amount. So if you're lazy and don't want to call around, you can just buy it from him and get it for $70 tonite.
Good luck