Cheapest Wireless mouse?

^^^^^

So....what's a good, cheap wireless mouse? Doesn't have to be optical.

http://www.atic.ca/index.php?page=LongDesc&sku=11420

$35 canadian

My grandma picked up a no-name wireless ball mouse at the local mom and pop store about 2 years ago, and its not bad for $8. You wont be gaming on it, but there is little to no lag and seeing as it uses a ball, it won't eat batteries. That would be the first place I would check on an extreme budget.