Can I help you? On Twitter, the answer is no.

Objective: Fix a slow remote and a screen prone to pixelation.

Twitter: I asked @ComcastCares about the remote and got a response from @ComcastBill three minutes later telling me to restart the system. I responded with another question about pixelation and was told restarting would work for that too. I said restarting wouldn't work, and within about 15 minutes I had messaged Comcast Bill my phone number and a signal was sent to my box.
Time: About 20 minutes total
Problem solved? Yes

Phone: Maybe I was calling on their off hours, but the customer service call was quick and easy. Same answers as Twitter.
Time: 7 minutes
Problem solved: Yes

Website: Connected via live chat fairly quickly and got the same response and another signal.
Time: About 5 minutes
Problem solved? Yes

Verdict: Telephone and live chat were be the winners here, but Twitter also solved my problem. Maybe Comcast has really listened to all those customer service gripes.