I've created osm2sqlite, a programme to convert from OSM files (OpenStreetMap's XML file format) into a SQLite database. It's not very good for display OpenStreetMap data in a GIS programme. It's good if you want to muck around with raw OpenStreetMap data, in a familiar SQL environment.

Code is copyright Rory McCann and released under the GNU GPL v3 licence (or at your option a later version)