If you're using Delphi 2009 or later Option Sets are a perfect solution for this problem.
Option sets are basically collections of settings that would normally reside in the DPROJ (which you do version) but instead stored in a .OPTSET file (which you don't version).
Make your DPROJ contain the settings that are common to all developers, that nobody is allowed to change unless it's an agreed across the board change.
Next in the project manager (D2009 and above) on first the DEBUG configuration node and then the RELEASE configuration node, right click and select "New Option Set". Call this option set something like "Local Developer Debug Settings.optset" and "Local Developer Release Settings.optset".
Now commit only your DPROJ to version control as it now refers to these .OPTSET files. You must name your option sets exactly the same on each machine for this reason.
When you want to make a local change to your project configuration rather than editing the project configuration, right click on the Option Set in the project manager and select "Edit Option Set".
The IDE will apply the changed settings from the option sets without modifying the original DPROJ. Settings are applied hierarchicly with option sets being the last to be applied.