This article claims to provide a method for getting the shutter count for the 7D.
In short, you install gPhoto2 and run the command:
photo2 --get-config /main/status/shuttercounter
Version 2.4.11 (released on Apr 17th, 2011) has been tested and works with 500D.
A little warning: under Ubuntu Linux, my first attempts failed because of the following error:
*** Error ***
An error occurred in the io-library ('Could not lock the device'): Camera is already in use.
*** Error (-60: 'Could not lock the device') ***
The simplest and quickest workaround to avoid the problem is to remove the SD card from the camera before connecting it to the computer and running the command.
Documentation in gphoto source code repository refers to shuttercounter parameter for the 1000D, 450D, 500D, 60D and 7D (as of 8th Jan 2012).
Since the 500D, 550D, 7D, 60D and 1100D are newer than the latest version of EOSInfo Utility, it might just be that its developer has yet to update for the newer cameras.