So, there's a couple of systems that I've been using fairly intensively in the last couple of months, both concerned with the programme for Agile 2008 (which is looking pretty good, BTW). 

One of them complains if one tries to browse certain URLs without having first logged in. In that case it tells me "You are not authorized to access this page". Which irks me every time I see it, because of course I am authorized to access that page, I just haven't yet presented the credentials that tell the system so. Which is what the system should invite me to do, rather than telling me to get hence.

The other system allows collaborative editing of documents and shows who last edited each file. When I am the person who last edited the file it says that the editor was "me". Which should, of course, be "you".

This sort of thing is a small, but I think under-appreciated, source of the discomfort that many people feel when using IT systems. We (I write as an implementor of systems) should be more careful in this regard.