diff --git a/README.md b/README.md
index 1c7bc8f..04e9803 100644
--- a/README.md
+++ b/README.md
@@ -24,3 +24,10 @@ Install and debug iPhone apps without using Xcode. Designed to work on unjailbro
 ## Notes
 
 * With some modifications, it may be possible to use this without Xcode installed; however, you would need a copy of the relevant DeveloperDiskImage.dmg (included with Xcode). GDB would also run slower as symbols would be downloaded from the device on-the-fly.
+
+
+## Listing Device Ids
+
+Device Ids are the UDIDs of the iOS devices. From the command line, you can list device ids [this way](http://javierhz.blogspot.com/2012/06/how-to-get-udid-of-iphone-using-shell.html):
+
+        system_profiler SPUSBDataType | sed -n -e '/iPad/,/Serial/p' -e '/iPhone/,/Serial/p' | grep "Serial Number:" | awk -F ": " '{print $2}'