Technology/Computers Research

Free:

ACM Digital Library (free to search, need subscription to view most content)

Scirus (allows export to citation manager software)

Scitopia

CiteSeer (a citation index)

SMEALsearch

World Wide Science

Science.gov (searches federally funded STM research)

Subscription-based:

Computer and Information Systems Abstracts

Inspec

Compendex

IEEE/IET Electronic Library (IEL)