Crunchbase.com is a great resource for this type of research. Try searching for companies in the categories you mention and see which investors are in those deals.
I've browsed around a bit there already, it's a bit tough to get peoples direct contact information though. Rarely ever can you get an email, usually a Twitter will help, but it's still not a surefire method. Thank you though, I'll be digging through CB more.
[+] [-] answerly|15 years ago|reply
[+] [-] yourfavwhiteguy|15 years ago|reply
[+] [-] tzm|15 years ago|reply