Glen Alleman posted on the difficulty (or otherwise) of the maths in EVM, and several of us commented. He followed that with an example in which the maths is very simple, which I quite liked as an introduction to Earned Value.
Marcin Niebudek wrote an article, in which he adds a budget line to an agile burn chart, measuring both in percentages. Nice to see I’m not the only one doing that. (Even if he does draw the chart up the "wrong" way ;-)
June 2011: another interesting one from Glen Alleman, on the relationship between the ANSI standard criteria and simple/agile EV.
July 2011: A nice burn chart example from the folks at Atomic Object. It doesn’t include the cost line, and I’d prefer if it did, but it does offer a clean solution to some of the challenges of charting change.