GIMP Script: Scale Pattern
Someone on GimpTalk was complaining that patterns weren't scalable so I though of a work-around.
I just wrote a script to take the current pattern, scale it and leave a copy in the clipboard. Gimp 2.6 lets you use the image in the clipboard as a fill pattern, so you can just use it from there.
You can scale from 20% to 500%
It uses Lanczos scaling working with a tiled copy of the image, so if a pattern is tileable the scaled one will be as well.
You can access the script by right clicking on a pattern and selecting "Scale Pattern..."