All of the following assume you're using my preferred toolstack, e.g. OSX, python, VI. If something doesn't seem to apply, it's probably because you're using a different tool!
What version is this library?
Probably something like
strings libhdf5.a | grep 'library version'
Other useful tools in this space are otool, lipo and nm.
How do I get OSX to stop checking because something was "downloaded from the internet?"
xattr -d com.apple.quarantine <file.app>
Note that the above needs to be executed as root.
How do I do stuff in R?
If you're a social science type like me, you might be interested in the following packages. Lots of times, you'll want to look at the summary of the results. Paul Gribble has published a well-considered article on repeated-measures designs in R. I recommend it!
How do I edit video in obscure formats for free?
After all these years, video formats are still a maze of proprietary this n' that. If you don't care about $30, just upgrade to QuickTime 7 Pro. Even if you have snow leopard, this will do things that QuickTime X doesn't do (as of Dec 2009).
But, if you are a cheapskate or an ideologue (or both), your best bet is probably mencoder (see the mencoder docs). For example, I wanted to rotate a 3gp video taken with a blackberry 90 degrees counterclockwise (i.e. 3 * 90 deg. clockwise). Unfortunately, this video used the proprietary samr codec (so many other programs wouldn't read it). This did the trick:
./mencoder -vf rotate=3 -o new-video.avi -oac mp3lame -ovc lavc ../old-video.3gp
Note that mencoder will always output to AVI. I probably lost some fidelity in there too... but not enough that I care.