I get asked a number of times a week to introduce entrepreneurs to investors and I always decline. How do I know what sort of investor you need? If I introduce you without knowing you, that's a weak endorsement at best. At worst, a poor showing from you would reflect badly on me. And besides, isn't figuring out what investor you'll work well with sort of your job?
Dan Shapiro nails it by saying, "'Hey, could you introduce me to some investors?' It’s sort of like when, on the second day of school, a goofy freshman asked me if I could introduce him to any girls."
Want an introduction? Figure out which investor you want to meet, be able to articulate why you think they're a fit, and then find out who in your circle knows them. Ask "I see you know Bob Smith. He's actively doing seed investments in my sector and I'd love to meet him. Can you introduce us?"
PS: Need a technical cofounder? You could safely substitute "technical cofounder" for "investor" in much of the above, too.