I have a client that needs to have different Toolbar buttons visible (or not) to different users/groups. For example, Managers, don't need any buttons apart from a Business Process 'Approval'.
Hi Jonathan,
Unfortunately custom toolbar buttons are not stored in the user attributes. These are stored in the registry under HKEY_CURRENT_USER. I think this is a limitation of how windows actually presents a program but I could be wrong there, that's just a guess.
If you want to roll out a standard setting to all users. The best way to do this would be using group policy or log on script or something across the domain that way to modify the registry at log on. This isn't something LF can handle on it's own.
Hope this helps point you in the right direction! 
Does this still apply to Client v9.x.x and newer?
Yes it's the same from V8 through 10.
Could you provide me the script please, Chris?
For Group Policy? The registry locations are listed above..
Sorry Jonathan, I'm not overly intimate with Group Policy to direct you in exactly the right place.
Thanks Chris, I had a feeling it was going to be a registry/ group policy job. 
Good stuff. Hope that answered your question 