Whatever gave you the idea that you can't leave a laptop on? I am in Las Vegas (Boulder Highway and Nellis), have 3 laptops (two toshiba and one Fiju) and a PDA on a home network, apt complex uses sat (no cable) and a switching phone system (no dsl), so I use an audiovox pc 5220 card in one of the laptops that gives me always on internet (NationalAccess in most places I travel to and BroadBandAccess ((EVDO)) here in Vegas), and except when traveling (and once for an hour or so during a power failure), it has been on continuosly for over a year. Got WiFi built in to your laptop? I run an always on open/free hotspot (SSID PP in LV, internet connection available when I am in town). For what it's worth, depending on the design of the laptop, it may get hot (some do some don't), but they make heat dissipating plates/bases/trays to set em on (got em at Fry's on Las Vegas Blvd, aluminum with ridges). If you are only gonna use it on one machine, no problem, if you want to share the internet connection on a network, be aware that the Mobile Office software addon specifically for the 5220 card stops sharing, but you can get around that very easily (check alt.cellular.verizon or email me at PeterPan at Akamail dot com). As for file sharing, it works fine with regular downloads, but has a problem with sharing on peer to peer networks.