I tried the other Bangladesh map posted here sometime in 2009.
However map of Bangladesh in that file is not very useful. It just has some names of some localities - no routable road - no meaningful boundaries.
The IMG file is not even 1MB - that should tell how much info it contains. So I was searching for a better version.

Anyway, I found the latest OSM version acceptable to some extent (current size is about 14MB although some adjacent part of India is also included).
It even contains some important POIs - of course complete POI database will take many years it seems. I am posting here the IMG file built on July 21, 2011.
I doubt that Garmin will release Bangladesh map any sooner.
If any of you find a better map please let us know.
Following is the download link:

[Only registered and activated users can see links. ]

Thanks.