Datasheet Repository:
Coming online this fall, once I get back to the world of 10Mbs Ethernet...
Manufacturers:
Analog Devices
Atmel
Benchmarq
Burr-Brown Corporation
Harris Semiconductor
International Rectifier
IXYS
Linear Technology
Maxim
Motorola Semiconductor Products Sector
Motorola - SPS Navigator
Motorola - Master Selection Guide
National Semiconductor
Philips Semiconductors Homepage
SGS-Thomson
Siemens Components Inc.
Siemens Semiconductor Group
Texas Instruments
Toshiba America, Inc.
Distributors:
Digi-Key
Jameco
Marshall
Mouser
Newark
Various Resources:
Electronic Design Pages
Transistor Cross Reference Database
Elektor Electronics Homepage (The BEST electronics hobbyist magazine out there)