I'm too much of a GIMP monkey to pass this up. Here's my entry:
Here's what I did:
1. Duplicate image
2. Threshold to create layer mask for treeline
3. Gaussian blur the mask, select all and copy
4. Back to original image, duplicate layer
5. Add layer mask (paste)
6. Blend mode "Multiply" at 100% to maximize sky
7. Merge down
8. Duplicate
9. Desaturate
10. Invert
11. Blend mode "Overlay" at 58%
12. Merge down
13. Duplicate layer
14. Layer mask treeline again
15. Invert layer mask (want to leave sky alone this time)
16. Blend in "Screen" mode at 40% (brighten foreground)
17. Duplicate base layer, move to top
18. Blend mode "Grain merge" at 40%
19. Merge all visible layers
20. Crop
21. Minor cloning on left arm and weed in the sky
22. Unsharp mask