Identifying British accents

1. Are there rules of thumb for pinpointing British accents regionally?
2. What other accents do Americans tend to mistake for British?
3. Are there good online resources that can help with this? Audio samples would be essential.

EDIT: Also, is there such a thing as a "neutral" British accent, analogous to American broadcaster's midwest pronunciation that is perceived to be the most free of regional characteristics.

Check this out in relation to the accent question. I find it extremely interesting to hear accents from different places.

Also, is there such a thing as a "neutral" British accent, analogous to American broadcaster's midwest pronunciation that is perceived to be the most free of regional characteristics.

The Cambridge pronunciation dictionary calls it "BBC English". Previously the term "received pronunciation" was in use.

Pin pointing British accents I would say would only come from familiarity and experience. Coming from the UK with a fairly neutral East Midlands accent and being a fairly regular visitor to the States in the past, my accent has been confused in order of frequency as Australian, South African, NZ, French and Russian. The most common response to hearing my voice in the States is "Cool accent... Where are you from?"

I would urge caution regarding using BBC news readers as a source of a neutral British accent as in recent years some regional accents have been quite commonly used. The current anchor for the 6 o'clock BBC news, Hugh Edwards is Welsh and his accent is quite distinctive. Better examples would be Moira Stewart or Sophie Rayworth. I agree that Richard Dawkins is a little on the posh side.