[BalinKing]

I think I pronounce the first and last a's the same (specifically, as /ə/)... it must be a dialectical difference (mine is General American English).

[nulbyte]

I've think I've heard bina:na:, bina:nɚ, and binænə, in addition to bənænə.

[smnrchrds]

I think you are right.

[zarzavat]

For me the first a is reduced to almost nothing, the second is a long vowel and the last is a schwa.