>>40 Main one right now is a HP Probook 6460b w/ an i5-2520M and 4GB of RAM. Yes some do here. In racks @ datacenters and IEEE 802.11s. Read their specs, and compare it w/ a modern i7-core tablet:
SDF uses DEC Alphas and AMD Opterons running NetBSD, TOPS-20 and Symbolics GENERA
You can run a ISP with just 3 laptops (one really, but you want to be able to have fail-overs, and one bridge).