Your Wish:

"Automatically have my DSL modem reboot when it hangs"

APC Automatic Power Cycle

Network-based Plug and Play AC power control appliance. Automatically RESETS AC power according to PING results. Includes network and RS-232 interface. Also very configurable for Internet, LAN or WAN use.

N-AC 1-2

Use with any browser to control the AC power locally or remotely (ON/OFF/RESET). Also automatic out-of-band telephone line backup and Auto RESET features. Plus USB and local/remote push button control.