I'm mostly interested in mapping bike paths in Mid-Michigan.
TIGER Data Cleanup
Since mkgmap supports routing now, I also began to fix up all the ugliness of the TIGER imports. I believe that the Lansing metropolitan area should have correct routing now (but I can't promise anything). In general the TIGER data was very accurate for this region, with a few notable exceptions in some newly constructed residential areas. In many cases, I even deleted points from the TIGER data because they described the ways in far too much detail.
NHD Data Import
The National Hydrography Dataset is one of the public domain GIS databases published by the US government. It contains information about lakes, rivers, marshes, and such, which would really make the map more useful. While I'm too lazy to get into the nitty-gritty details of the NHD import, I would gladly "adopt" some areas in Michigan and merge the import with the existing data.
I also started to map the campus of MSU in great detail. I use it as a "training ground" to practice fancy new tagging schemes.
Please feel free to contribute!