i've heard all the "wireless mice and keyboards lag" talk before. technically, yes there might be a very slight delay depending on the technology used but if you have a good set its barely even noticible. i used a wireless set for years and routinely trounced people with wired sets.
this goes back five years or so but i had a logitech mx1000 mouse/keyboard set which i used for about 3 years (it still works though). i since changed to a wired keyboard and mouse but i cannot say there is any better response than the set i used before. i should mention that i had the wireless and wired set hooked up to my ps/2 ports.
in general i'd stick with one from logitech as they seem to do wireless right. personally i'd have to say go with one that has a larger base receiver you put on the desk instead of any micro-receiver types (if they exist) like the ones found on some wireless mice as the range might be less.
Thanks! Off of your advice I was stuck between these two.http://www.newegg.com/Product/Product.aspx?Item=N82E16823126188http://www.newegg.com/Product/Product.aspx?Item=N82E16823126199
Would you recommend something else? I'm not interested in a mouse, so that doesn't matter. I was strongly considering the solar one, but read something about the constant recharging/discharging becoming a problem, so than I started looking at the other.