In several modifiers, constraints etc. you can select object they're affected by (for example Armature, MeshDeform, Mirror and Lattice). It would be more natural to click into that text window and then click on the object you want to select.

When you bake fluids, in the top menu there shows a progress bar. But this doesn't happen for any other simulation/calculation.

What I can think off this applies to: cloth, particles, decimate, boolean, unwrap for very complex meshes, render baking, softbodies, compositing nodes

The "pivot individual centers" works fine for individual separate faces, but very weirdly for bigger regions. The understandible way would be to find all islands (this applies for edge/vertex select mode also) and transform them individually.
It would also fix this request: http://www.blenderstorm.org/qapoll/ideas/idea/72/ .

Multires should (optionally) smooth UVs also. Subsurf handles the smoothing perfectly, so where's the problem?

Large free space in the scene slows down raytrace rendering a lot. When I have some objects far in the background, to avoid this slowdown I have to set all their materials as not traceable. When I forget just one tiny object it has the same impact.

The most convenient solution would be to select a box within raytracing works and outside of it doesn't work.

I know it's impossible to have this feature physically correct, but it could be used for some tricky work-arounds.
An example could be making hot air effect using a lot of raytransparent planes with circular IOR texture.

When I want to use an image (usually a blueprint or a background) from the web I have to download it to my disk and then find it in the Image browser again. It would be a bit easier just to give blender a link from the net - the image would be automatically downloaded and packed into the scene.