Set -q and it will only show when you find a block or submit a share. So solomining you will only successful blocks
Well, that's wise, but now I cannot see my hashing speed.

That a choice you have to made.
However, the speed never change (from my experience), so once you know what is your speed for your cards, there isn't much point to continue to display it.
I think using ">> log" (or something like that) should give you the full logfile (in linux playing with tail and grep could help you to achieve what you want... but in windows I am totally clueless)
@nomad1109: Thanks for the BTQ, you quadrupled my balance.
[Your startup command] 2>&1 >> logfile.txt
That will redirect standard output (1) and error output (2) to a single logfile where it will append to the end of the file rather than overwrite what is there.
You won't see anything on the screen anymore, but you will log all the output to a file you can search through later.
There is a way to put the output to both, but it can require some more setup or specific needs on your end...
[Your startup command] 2>&1 | tee logfile.txt
Hope that helps.
Excellent explanation and great community. Thank you all!