Back in April I posted about what to do if the disk your Exchange transaction log files reside on runs out of space. This was all done through the eseutil utility.
If you are not comfortable with this tool or would simply prefer a GUI-based way to do it, its possible to acheive the same result through the Exchange Troubleshooting Assistant (2003 or 2007).
There is a great post here which documents how to do it.
Something tells me I may well need to use this again sometime in the future.......