The GetSETWomen Blog is a great source of inspiring women in technology to blog about for Ada Lovelace Day.
The UKRC's GetSETWomen network for women in science, engineering or technology (SET) site also includes an astronomy blog where a variety of women will post 'a one-off entry about the role of astronomy and outer space in their lives' for the International Year of Astronomy, and the 2008 Outstanding Women in SET: Photographic Exhibition is another good source. It's a shame they haven't listed the 'outstanding women in SET' for 2009 ahead of the launch of the exhibition but check back in mid-March.
[Updated to add:] The Global Women Inventors & Innovators Network(GWIIN) website might also throw up some leads, and the related British Female Inventor of the Year award site has some great stories about women inventors.
I've also been listing inspiring women at modernbluestocking.freebase.com, though as it's a much broader project, not everyone listed works with technology.
If you're not sure why female role models matter, these articles explain it well.
I should be studying for exams but I wanted to quickly post about Ada Lovelace Day. The organiser asks for pledges to "publish a blog post on Tuesday 24th March about a woman in technology whom I admire". You can find out more about why at the link above, but the point about why role models are important is worth repeating:
Undoubtedly it’s a complex issue, but recent research may shed some light: Psychologist Penelope Lockwood discovered that women need to see female role models more than men need to see male ones.
Well, that’s a relatively simple problem to begin to address. If women need female role models, let’s come together to highlight the women in technology that we look up to. Let’s create new role models and make sure that whenever the question “Who are the leading women in tech?” is asked, that we all have a list of candidates on the tips of our tongues.
Thus was born Ada Lovelace Day, and this pledge:
“I will publish a blog post on Tuesday 24th March about a woman in technology whom I admire but only if 1,000 other people will do the same.”
Who would you blog about? I've signed the pledge so I'd better start thinking.
[Edited to add: if you're interested in researching and making information about inspiring female role models accessible, you might be interested in 'modern bluestocking'. Contributions and suggestions are very welcome, especially from a technical perspective. And I will be shamelessly checking out suggestions for Ada Lovelace Day to add to the nascent modernbluestocking topic on Freebase.]