You might want to try Damn Small Linux. Normally DSL is run from either a CD or USB stick. The entire distro is about 50MB in size and runs quite quickly on old hardware. Actually, it's the only distro I have experience with which runs quite fast straight from the CD.
You can install DSL onto your laptop using the included installer and its footprint is quite small. Since it's based on Debian you should be able to get any wireless drivers quite readily.