Despite being an Ubuntu user for many years, for several years I have been using Picasa on Windows to make photo collage grids of my photos.
The process for doing this is to select either a folder of photos or a number of photos and press the "Create Collage" button. The photos are usually arranged by date taken (which I prefer), but this can be changed by manually rearranging them. The results look like this:
Click here for a bigger version
Is there native software - i.e. doesn't require Wine or run in a browser - with a GUI (for easy editing) available for Ubuntu that can make collages in the same way?