Continuing the "deep blue sky" theme, here's another one, and this one, better than yesterday's, demonstrates that polarising filters can be quite effective in deepening the colour of the sky.
Update: as a couple of people have asked I've put up the original version of this shot here:
All I did with this one was up the contrast with the Curves tool, boost the saturation a little with Hue/Saturation, and use another Curves adjustment layer to put a bit of colour (and a bit more contrast) into the woodwork in the foreground.
11.38am on 2/8/05|
EF 17-40 f/4L USM
17mm (27mm equiv.)