I've always wanted a feature to be able to pull up recently opened files. Here is a patch that adds this to the File menu of the editor:
Created an issue in the google code issue tracker:
EDIT: This patch is broken (I broke it when I added truncating file names), see below
Quick question, how do you apply the patch?
I don't know what your background is, but to give a broad outline, you have to apply to the java source downloaded from github then rebuild the Arduino project.
To apply the patch, use the 'patch' command from the command line on unix, or cygwin. Or you can use the command 'git apply'
Typical usage would be:
$ cd <root of the source tree>
$ patch -p1 open-recent-file.patch
Then use 'ant' to re-build the project.
You could also pull the branch I posted from github just compile it if you just want to see what it looks like.
Updated patch attached. Previous version saved filename with '...' characters in it, which you couldn't re-open, of course.