Not really a custom action, but I've created a deployment tool that scans the specificied domain for computers, creates a c:\temp folder, copies the lsclient to that folder, and executes it. It lists the computers with checkboxes, so you can select multiple computers (as well as buttons that let you select all and clear all).
If anyone is interested in this tool, let me know and I'll clean up the code (some of it is hard-coded) and upload it. It requires the latest .Net framework and psexec.exe
Edit : lastest version attached below.
