I'm installing and configuring Tridion 2011 SP1. There are now so many databases, that it's just insane to try to keep track of them all by hand, but nil desperandum, the power shell is here. OK - you might not be quite so compulsive/obsessive, but I threw together a script that lets me have a list of verified working logins before I start poking at config files. At the very least, it brings out some findings about consistency across the different products. Here's what I did:

function CheckDatabase($connStringBuilder, $queryString="select DB_VERSION from TDS_DB_INFO", $CommandType="Text"){
  $conn = new-object System.Data.SqlClient.SqlConnection
  $conn.ConnectionString = $connStringBuilder.ConnectionString

  $conn.Open()

  $comm = new-object System.Data.SqlClient.SqlCommand
  $comm.CommandText = $queryString
  $comm.CommandType = $CommandType
  $comm.Connection = $conn
  $reader = $comm.ExecuteReader() 
  $readResult = $reader.Read() 
  $dbversion = $reader.GetString(0)
  $reader.Close()
  $Conn.Close()
  $dbName = $connStringBuilder["Initial Catalog"]
  if ($dbversion.length -gt 0) {"$dbname Database version found: $dbversion"} else {"$dbname fffft"}
}


$connStringBuilder = new-object System.Data.SqlClient.SqlConnectionStringBuilder
$connStringBuilder["Data Source"] = "MY_LAPTOP\DEVELOPER"
$connStringBuilder["Initial Catalog"] = "Tridion_cm"
$connStringBuilder["User ID"] = "TCMDBUSER"
$connStringBuilder["Password"] = "Yes I used the same password for all dbs - don't you?"

CheckDatabase $connStringBuilder


$connStringBuilder["Initial Catalog"] = "Tridion_Broker"
$connStringBuilder["User ID"] = "TridionBrokerUser"

CheckDatabase $connStringBuilder

$connStringBuilder["Initial Catalog"] = "Tridion_cm_email"
$connStringBuilder["User ID"] = "TMSDBUSER"

CheckDatabase $connStringBuilder "select DB_VERSION from OE_DB_INFO"

$connStringBuilder["Initial Catalog"] = "Tridion_submgmt"
$connStringBuilder["User ID"] = "TMSSMUSER"

CheckDatabase $connStringBuilder "select DB_VERSION from DB_INFO"

$connStringBuilder["Initial Catalog"] = "Tridion_tracking"
$connStringBuilder["User ID"] = "TMSPSUSER"

CheckDatabase $connStringBuilder "PS_READ_DBINFO" "StoredProcedure"

$connStringBuilder["Initial Catalog"] = "Tridion_TranslationManager" 
$connStringBuilder["User ID"] = "TMUser"

CheckDatabase $connStringBuilder "SELECT DB_VERSION FROM TM_DB_INFO"

$connStringBuilder["Initial Catalog"] = "Tridion_Ugc"
$connStringBuilder["User ID"] = "TridionUgcUser"

CheckDatabase $connStringBuilder "SELECT DB_VERSION FROM UGC_TDS_DB_INFO"

And here's what the output looked like:

 . C:\Users\Administrator\Desktop\dbTest.ps1
Tridion_cm Database version found: 6.1.0.0
Tridion_Broker Database version found: 6.1.0.0
Tridion_cm_email Database version found: 2.2.0.0
Tridion_submgmt Database version found: 2.2.0.0
Tridion_tracking Database version found: 2.2.0.0
Tridion_TranslationManager Database version found: 3.0.0.0
Tridion_Ugc Database version found: 6.1.0.0

All in all - maybe not worth the effort, but somehow satisfying. Is it useful? Maybe.