In lock screen of qt_wallet, I just found that I can do the following things (now I am using 0.4.2 in ubuntu):
1. right click mouse, press "Go Back"
2. the wallet will really go back to the tab before screen locked, and there are a couple seconds before re-lock (this interval may vary depending on the final tab you are while pressing lock).
3. I can prepare a command in my clipboard, paste it, and hit ENTER. This step may require performing step 1-2 for multiple times.
I think basically the information of your account can be obtained using step 1-2 (account names in wallet, transaction histry, etc), and can do something more using step 3