William Wake explains a simple protocol for getting unstuck in a development team: The Humble Yo. In the explanation is a nice story and some graphs showing why it is better to interrupt the whole team for a moment, than to remain stuck on your own (or with a pair-programmer).

Using an agreed-upon protocol has the effect that People don't resent interruptions as much; they already gave permission for it. Another effect of agreeing on the protocol beforehand in my experience is that everyone on the team is aware that it is alright to admit you are stuck or don't know the answer. This lowers the barrier to ask for help a lot. Asking for help takes courage, but works much better in the long run - I see it as an opportunity to invite the whole team to work together on a problem, which usually creates solutions none of the individuals could have invented themselves.