ish, you could buy a new router with better wireless performance which would cost about £50 but I think your main problem is the wireless adapter in your laptop or whatever it is you are using. You be better off replacing that first.
Something like this would be good
http://www.dabs.com/products/linksys...83-50468&src=3
That being said, if your computer/laptop is permanently sat next to the router I would strongly suggest leaving it connected to the router by the patch cable, it is going to save you loads of hassle.