SAP who has access to what?
To quickly check who has access to a particular object in an SAP system try executing program RSUSR002.
I needed to find out who has access to transaction SMQ1 and managed to accomplish that by filling in the following parameters in the first screen:

RSUSR002
When was the last System Refresh done in an SAP system?
To quickly check when your DEV/QA system was refreshed from a production box perform the following steps:
- Execute the transaction SCCL
- Fill in the Source Clinet filed [ie: 001]
- Select <Goto> <Log display> from the main menu
You should see a screen with a list of dates of when the system was last refreshed.
Other useful transactions:
SCC9: client copy – copy a client
SCC8: client export
SCC7: client import
SCC1: copy as per transport request