P2P

So my job has necessitated that I have a Windows machine. I got my mom's old laptop (like 3 years old...) and I've done a lot of work on it software-wise (upgraded to XP Pro, added Office 2003, completely reworked the interface to make it look, act, and sound like Vista, etc). But it's been a while since I've seriously played with a WinBox (or WinBook as it were). What is a good file share program that can hit the LimeWire network? I use Acquisition on the Mac, and I love it; it's light on system resources, no adware or spyware, good results, etc. I'm looking for something similar for this lappy. Any ideas?