Inspired by Goomboo's heatmap of profits, I wrote a Python script to automatically draw similar heatmaps for custom time periods. It works on Linux as this is the only OS I use. Anybody is free to adapt it to work on other systems (sorry, I have neither experience nor wish to do this).
Here's an example of what is drawn:

The script itself may be found on Github:
https://github.com/Queeq/stockI would also be happy to get advice from experienced Python programmers on how to make it better.
If somebody is interested in particular period but is too lazy/busy/inexperienced to draw graphs himself, I can do that for him and post it here. Required parameters are: time period with maximum resolution of one day, size of ticks to work on (5 minutes, 15 minutes, 30 minutes, 1 hour, 2 hours),
Currently I used it only with BTC-e historical data taken from
Bitcoincharts, but it would work with every CSV-formatted historical datafile.