Thurman (happy birthday) has a post on how he found his current church. Having been there, I know how welcoming it is.
I don’t know if there is a tradition of mosque moving for Muslims. I know we don’t move as freely between Shi’ah and Sunni, or even amongst Shi’ah. However, I get the sense that moving amongst the Sunni schools is more normative in the US simply because most people are not as aware of the madhab as they should be. However, there are mosques where you can definitely made to feel unwelcome (96th and 3rd, ahem).
I wonder what we as American Muslims are willing to do to find a spiritual home? Or do we just drive people away?