Useful Links
Linear Technology LTspice:
A free op-amp simulation tool
Mancini, R., ed. Op Amps for Everyone: Design Reference. Texas Instruments, 2002. (PDF - 2.0MB)
An excellent reference book for op-amp design.
OpAmps: Active Filter Synthesis Design Tool
A simple tool from Analog Devices for designing active filters using voltage-feedback op-amps.
Sensors Web Portal
References, hints, sources from the International Frequency Sensor Association (IFSA)
Robotics related products compiled by Kevin Dowling
Bill Buxton's Directory of Sources for Input Technologies
Conferences
Sensors Expo
Big trade show with tutorials and proceedings
IEEE Sensors
Very large new state-of-the-art sensors conference
SPIE
Old standby conference for sensors and applications
Transducers
Emphasizes MEMs, but like IEEE Sensors
UIST
ACM conference on user interface technology
SenSys, ISPN, etc.
Sensor net conferences — not sensors...