Siemens knows that driving is really hard with a phone, PDA, GPS and stereo to worry about, so they've invented a system to read signs for you.
A camera scans the field ahead while an onboard computer searches for patterns. In the case that a speed limit sign is detected, a windshield display will place the new speed limit next to your current rate of travel. The system can also be configured to automatically adjust your cruise control accordingly if you are a "slowpoke".
Look for it in 2008 - after you're too poor from moving violations to ever afford it.