A long time ago, I signed up for Blogger and Google Analytics using email address (A).
Later on, I got a Gmail account; that's email address (B), which is also associated with Google Reader and Google Docs.
And last week, I ditched POP mail for Google Apps; email address (C).
Earlier today, a client sent me an authorization email for his Adwords campaign. When I clicked on the invite, Google tried to log me into (A) before giving me a cookie error. At the time, I had two other browser tabs open for Google Reader (B) and Gmail (C). When I accepted the Adwords invite under (C), Google Reader switched over as well, and suddenly I had 0 feeds.
I would love to consolidate under (C), but Google Apps doesn't support every possible Google service just yet. Is there any other solution besides living with my multiple identities?