OpenStreetMap
I wonder if there's any place that has a list of places to check; I found a road at osm.org/edit?editor=remote&lat=42.14573&lon=-88.0402&zoom=15 that doesn't line up at all with the satellite imagery, and while I was thinking to go and check for myself, I was thinking it would be nice to have a centralized place where people can add a "hey, this might not be right" area.
Discussion
Comment from z-dude on 17 October 2011 ла 02:09
usually, people add a 'fixme' tag to things they think should be fixed in the future. Ie, you add half a trail.
http://keepright.ipax.at shows fixme tags, as well as common mistakes such as errors caused by bad imports.
There are several quality tools out there. osm.wiki/Quality_Assurance
I think there's also a site which highlights 'unmodified tiger import' so people know to check tiger imported data (usually, the nodes don't connect to manually added roads, or are low resolution)
Comment from Takuto on 17 October 2011 ла 05:47
http://openstreetbugs.schokokeks.org/ - very useful tool to post "bug" markers. They can be seen after that in JOSM editor, also in Osmand navigation program. Sadly, AFAIK there is no history layer - after bug was closed it stays on map for a week, then dissapears without trace.
Comment from tachoknight on 21 October 2011 ла 00:13
Those are great sites; it'd be good if there was some link from OSM to them directly, or put together something equivilant on the OSM site for others to use