WirelessKeyView is a tiny portable tool which instantly recovers and displays all your stored wireless network security keys/ passwords.
A table presents detailed information on every item: network name (SSID), key type (WPA-PSK, WPA2-PSK, WEP if you can find an old enough system), the key in ASCII and hex forms, the adapter name, encryption and connection types.
The table also has a "Last Modified" column, handy for computer forensics. Click the column header to sort by that field and you'll see when each network record was created or modified. If a laptop accessed a hotel wifi for the first time last week, for instance, you'll see the precise date here.
Some or all the keys may be saved for easy access later. Select whatever you need, right-click and choose Save to save them as a report, or Copy to copy them to the clipboard.
WirelessKeyView isn't a program most people will use very often, but at 57KB it's not going to tie up much drive space, and if you do need to find your wireless keys it'll do the job with ease.