As a i already mentioned before, manual focussing with most new digital SLR's viewfinders is (at least to me) a difficult thing to do in low light situations. My Pentax K10D's viewfinder is said to be comparable bright and big but at certain concerts i just wasn't able to get the focus right. Especially when musicians keep moving all the time and/or your (C-) autofocus does not work fast enough because of the little available light shooting often becomes a trial and error.
I have to mention that I almost never use a flash and so I have to use small apertures (=small DOF) so my chances to hit tend to be very small (as you can see on most of my concert-photographs,hehe).
One and half a week ago i discovered an ebay-dealer from China who sells focussing screens that fit into the K10D (and K100D/Ds) and due to the fact that 25 Euro were not that much money i ordered one. It arrived today and after inserting it and doing some testshots I have to say that it seems to work flawlessly!
The dealer offers screens for other cameras as well. I'm not sure if advertising him here is allowed, so just drop me line or just search for "Mattscheibe" and your camera-type at ebay.de and find out by yourself.
Oh, in case you're wondering what I'm talking about:
www.praktica-collector.de/images/BX_focussing_screen.jpg
Furthermore I just created a new group called "Everyday's Beauty".
Here's the description:
"Are you tired of photographs from far places that you might never ever see in your real life?
Well...I'm not, but I'd like to remind you that there is beauty in everyday day life, too.
This group is for extraordinary pictures of ordinary things everyone of us might see or use everyday.
No cats/pets/skys/whatever...please!"
Look here, if you are interested!
dan.