I currently have to book my time to the nearest 5 minutes - no, don't laugh, it's proved quite useful when estimating other jobs. But I have a problem.

If I am discussing Project A with colleagues, and at the same time my hands and keyboard are doing a code fix on Project B, which do I book the time to? How about if I'm also reading an email about Project C (and mentally drafting an asnwer to it)?