[OSM-newbies] Track changes in OSM

[Sebastian Arcus]

I've used JOSM about a week ago to add some buildings to OSM. Or at 
least I think I did - as looking at the same place again now they seem 
to have disappeared. How can I find out if I really did add them there, 
and if they were deleted? I have found OSM History Browser and OSM 
History Viewer in the wiki - but they require a way or node ID. As these 
elements have been potentially removed, I don't have their ID's. How 
would one go about finding out what was once in an area of the map? I 
have uploaded quite a few changesets in the last week - so trawling 
through them might be very time consuming. Any other way?

Sebastian