I bought the mk360 Logitech Wireless Combo keyboard and mouse for the office computer yesterday. It was only $34.95 at Walmart. It was the cheapest one they had, and I think I like it!
The mouse is better than the old one by far. It is very smooth and responsive. And, really, wireless is the only way to go with a mouse anymore (especially on a laptop).
The keyboard is definitely nice too. It's a "compact" keyboard, which is nice since the laptop keyboard already takes up some space. It's actually the same width as my 15.6" laptop, and I can just set the top edge up on the front of the laptop to give it a good slant to type on. The best thing about the keyboard over the one on the laptop is the raised (or framed) keys. The Lenovo keyboard has really flat keys and it's hard to tell where I'm at on the keyboard just from feel. This Logitech keyboard also supposedly has a 36 month battery life. It runs on 2 AA batteries - which came pre-installed.
It was super easy to set up. Both the keyboard and mouse came with batteries in them, and I just plugged in the usb receiver and it worked. I love the tiny usb receiver too. Unlike my old wireless mouse which stuck out about 4 inches when plugged in, this one only sticks out maybe half an inch. So you can leave it in even when moving the laptop around. You're also supposedly able to connect up to 6 items through it.
Overall, I would recommend this little wireless keyboard and mouse. It is hard to beat 35 bucks, and it seems to work great!