Amateur Radio
IRLP - Internet Radio Linking Project (more secure than EchoLink and more prefered.)
EchoLink - Another system for linking radio systems via the internet.
CARES - Cupertino Amateur Radio Emergency Services
ARRL - American Radio Relay League. The largest amateur radio organization in the US and probably world.
QRZ - A lot of good amateur radio related information and resources. Like call sign look ups.

 

Recreation
Hollister Hills Offroad Park - One of our favorite day trip wheeling locations
California OHV - California Off-Highway Motor Vehicle Recreation Division
Mt Madonna County Park - Our favorite camping spot :)
Sata Clara County Parks Homepage - Santa Clara County Parks Homepage. Good for finding biking/camping spots in Santa Clara County. (Only county run parks)
Portola State Park - Another good camping spot.
California Parks Homepage - California State Parks main page. Good for finding biking/camping spots in California. (State run parks only)