Thank you for the great replies.
Being in the Silicon Valley, the job keeps me at work till late (7pm) every day. I like to volunteer (environmental causes, vegetarianism, etc.) but it takes time to find a good vol group with interesting people. I live in the southern part of the peninsula, which is a total sausage factory.
I chose online dating sites like Nerve.com because the quality of the women seemed higher. I'm looking for women who'll be more compatible, and with online sites, I can (for example), see who's a non-smoker, has a graduate degree, has no kids, etc. In real life, it is difficult to meet and ask these questions in a reasonably small amount of time. I like rmarshall's suggestion of different profiles; I'll try that out.
Please keep the suggestions coming..