...Thanks for your replies so far
The wireless logitech mice seem most relliable.
Unfortunately, the Logitech MX1000 does stretch out across my budget, and although it's laser and outstandingly precise, I think a conventional wireless optical mouse at a lower price can do the trick.
I'd rather a cordless/wireless optical mouse, and have been looking at the Logitech MX700. Any good folks? I think it's just the wireless version of the MX500 range.
However, the MX700 is priced around the average of the laser MX1000 mouse, but they do have cheap bids going on ebay for the MX700. Not sure if I should be adventurous and bid