Snippets
Here are a few tidbits of code I've found useful at one time or another.

First, to determine your public IP address, the following 4 lines will do the trick:
Forum Topic
UrlDownloadToFile,http://www.netikus.net/show_ip.html/,%TEMP%\ip
FileReadLine,IP,%TEMP%\ip,1
FileDelete,%TEMP%\ip
MsgBox,4160,Public IP,%ip%

Second, if tooltips are being displayed beneath the System Tray making them unreadable, 1 line of code can put them back on top!
Forum Topic
WinSet,AlwaysOnTop,,ahk_class Shell_TrayWnd

Third, to find lots of information about your computer use this snippet of code:
RunWait, %comspec% /c systeminfo > tmpFile,,Hide
FileRead, var, tmpfile
FileDelete, tmpfile
Gui, Add, Edit, w600 h600, %var%
Gui, Show
return
GuiClose:
ExitApp

NOTE:
The above method of capturing data from a Windows command line utility can be used to retrieve a plethora of useful information such as:
WorkGroup Name
Internet Connectivity
Network Drives
MAC Addresses
• and much more.

Tip: see this forum topic for an example of a relatively simple method to retrieve command line output without a text file.

For a list of the available command line utilities see the A-Z Index. You may also want to refresh your memory or learn more about The Command Line in Windows.