Well, in short I can point to this map:
This map is very good. However, a few things are missing.
The island of Suðuroy (south of the turquoise line) has two more differences from the rest of the islands:
In Suðuroy short ø is pronunced [Y] instead of [9] as in the rest of the country.
Æ's history as being derived from ON É is very audible in Suðuroy, since long æ is pronunced [e:] and short as [E] (which is identical to how E is pronunced)
Furthermore, still in Suðuroy, -ir and -ur are in some dialects often pronunced [or] or [2r].
[n:] -> [dn] is also more common here. Most people further north would pronunce 'ánni' (definite dative of á (river)) as [On:I], where as in Suðuroy it's pronunced [OdnI] (like the name Árni).
Particularly in the capital dialect and the dialect of the 2nd biggest town, Klaksvík, the -ur and -ir endings seem to have merged to [Ir].
Tórshavn-dialects of pronunced unstressed -u the same way as unstressed -i [-e]/[-@], which means, that '(eg) komi' (I) come, and '(teir) komu' (they (pl.m.)) came may actually rhyme.
In the dialect in Gjógv, which is the northern most village on Eysturoy, 'vit' and 'tit' (we, you (pl)) are always pronunced with a short i, where other dialects have long i: [vIt_h], [tIt_h] <> [vi:t] [ti:t]
Many dialects also have short í/ý as [U]. In the capital is usually a shorter version of the diphthong [Ui] (which is how long í/ý is pronunced).
I think, that should cover it. I'll post more if I remember something, or some of you ask the right question(s).
Johan Petur
Gløgt er gestsins eyga. (Føroyskt orðafelli)
Wise is the stranger's eye. (Faroese saying)
L'occhio dell'ospite è acuto. (Proverbio faroico)
Hosťovo oko je múdre. (Faerské uslovie)
Fluent: Faroese, Danish, English, German
Almost fluent: Norwegian, Swedish
Basic: Slovak (studying), Spanish
Have studied: Hebrew, Russian
Interests: Ukrainian, Romanian, Italian, Albanian, Armenian, Ossetic, Hungarian, Estonian, Baltic languages