OK, I've got one more!  :) 

I put together a web application to help with maintenance mode.  This was my first attempt at building a web application so I'm sure there are inefficiencies and better ways to do it - so be kind with the comments!

I wrote this tool because I haven't seen anything that allows you to setup maintenance mode for remote systems without either having to logon to the RMS, use the operator console or install software/powershell on the remote systems.  This utility does a few things

-Operates on both individual agents and groups
-Allows 'right now' configuration of maintenance mode
-Allows future scheduling of maintenance mode
-Displays systems currently in maintenance mode
-Seems to work for both OpsMgr administrators and standard, non-OpsMgr, users by making use of the account configured in the web page application pool.  I say seems because I've only done limited testing!

I don't know if I will update the tool further and it is provided AS IS without warranty or support.  Feel free to update it yourself if needed.  I started a logging section but ran out of time so just commented out what I had.

 Get MMScheduler.zip
http://cid-3762f206d81ec57e.skydrive.live.com/self.aspx/.Public/MMScheduler.zip