I have two Google accounts, my main one which is used for Drive (formerly docs), Calendar and also a lot of 3rd party apps via the 'login with Google' feature.
The other Google account I use for my email on Gmail (although the account is under a custom domain running on Google Apps for Business).
The problem I'm having is that although I can have multiple accounts signed in in a browser, when you move between products it tends to stick in the same account. So if I'm using account-A for Drive, and I switch to Gmail, it stays in account-A (even though account-A doesn't have Gmail set up).
I then have to change to account-B in the top right corner. Is there a way to specify a default account for different products?
In other words,
use account-A for Drive and Calendars
use account-B for Gmail