django-hstore

You need dynamic columns in your tables. What do you do?

Create lots of tables to handle it. Nice, now you'll need more models and lots of additional sqls. Insertion and selection will be slow as hell.
Use a noSQL database just for this issue. Good luck.
Create a serialized column. Nice, insertion will be fine, and reading data from a record too. But, what if you have a condition in your select that includes serialized data? Yeah, regular expressions.

Projects using this package

django-rest-framework-hstore: django-rest-framework tools for django-hstore
Libreborme: django web platform that opens data from the Spanish Companies Register by providing also a search engine
Nodeshot: extensible django web application for management of community-led georeferenced data - some features of django-hstore, like the schema-mode have been developed for this project