I wrote a Greasemonkey script to upload Flickr photos using flickr2commons.
There are 3D models on Wikimedia Commons! This is a useful (but lesser-known) feature of this site.
My current to-do list on Wikimedia Commons
edit- Try to clean up some cases of overcategorization by using the Commons:Cat-a-lot tool. There are dozens (if not hundreds) of redundant categories that now exist.
- Repair some incorrectly formatted hatnotes
- Categorize some images in Category:Media needing categories
- Categorized some uncategorized books