I ran across this gem today, though I'd blog it before I lost it.
This script will create a table of all SQL Logins, and the DBs that the logins have access to.
CREATE
TABLE
_LoginDBMapping (
LoginName nvarchar(
max
),
DBname nvarchar(
Username nvarchar(
AliasName nvarchar(
)
INSERT
INTO
_LoginDBMapping
EXEC
master..sp_msloginmappings