A recent ASRS report submission (Aviation Safety Reporting System) published an incident where the crew did just this - takeoff with flaps retracted in a 737NG.
Here is the link to the ASRS page:
http://asrs.arc.nasa.gov/callback_issues/cb_320.htm
Here is a cut and paste of the report...
This B737-800 flight crew was interrupted twice while running pre-departure checklists, and a cockpit warning device that could have alerted them to the aircraft’s unsafe configuration, failed to function.
* …We performed the After Start checklist and the First Officer called for taxi. As we started the taxi, I called for the Taxi checklist, but immediately became confused about the route and queried the First Officer to help me clear up the discrepancy. We discussed the route and continued the taxi...We were cleared for takeoff [on] Runway 01, but the Flight Attendant call chime wasn’t working. I had called for the Before Takeoff checklist, but this was interrupted by the communications glitch. After affirming the Flight Attendants [were] ready, we verbally confirmed the Before Takeoff checklist complete. On takeoff, rotation and liftoff were sluggish. At 100-150 feet as I continued to rotate, we got the stick shaker. The First Officer noticed the no-flap condition and placed the flaps to 5 degrees. The rest of the flight was uneventful. We wrote up the takeoff warning horn but found the circuit breaker popped at the gate.
The cause of this potentially dangerous situation was a breakdown in checklist discipline attributable to cockpit distraction. The Taxi checklist was interrupted by my taxi route confusion. The Before Takeoff checklist was interrupted by a Flight Attendant communication problem. And for some reason, the takeoff warning horn circuit breaker popped, removing the last check on this sort of thing…From now on, if I am interrupted while performing a checklist, I intend to do the whole thing over again.
Another procedure used by many pilots is to stop (hold) the checklist at the item where an interruption takes place; when the checklist resumes, repeat the last completed item and continue with the rest of the checklist.
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One notable incident similar to this one resulted in a crash during the late 80's at DFW; a Delta 727-200 (happened right after the Delta L-1011 wisdshear crash in DFW). The crew forgot to set the flaps, botched the checklist, stalled and crashed after liftoff killing most of the occupants on board.
I would hazard to guess the more powerful thrust to weight ratio on the NG and the generous wing area, among other probable lucky details, resulted in a routine safety inquiry rather than fatalities as above.