For Umlaute to work in rxvt-unicode (urxvt) with zsh I had to add "export LC_CTYPE=en_US.UTF-8" to my .zshrc file and reconfigure locales to a default (en_US.UTF-8 rather than having none as default) with the "dpkg-reconfigure locales" command.

You may be running out of disk space fast if you have small SSD start partition on OS X Lion if you leave MobileBackups enabled.
If you open Terminal and run the command "df -h" you might see the (otherwise hidden) directory .MobileBackups using up a lot of space.

This feature is described in the Ars Technica OS X Lion review for example. It is there so your laptop will run backups even when you're on the move with no backup disk attached.

To disable it, run the command "tmutil disablelocal" in Terminal.
To enable it, use "sudo tmutil enablelocal"

This MacBook (black 2 GHZ Intel Core Duo) would not accept the firmware password I just set via the Firmware Password Utility from the Recovery Partition in OS X Lion 10.7.2.

The following steps let me turn off the firmware password protection. It only works if you haven't forgotten the password you had set. I my case this means I had used the correct password but it wasn't accepted. Seems like a bug, maybe specific to my particular (and rather old) hardware.

1. Open Terminal and type diskutil list
2. Mount the Apple_Boot Recovery HD partition with diskutil mount disk0s3 (use the identifier you see listed)
3. In Terminal type: open /Volumes/Recovery\ HD/com.apple.recovery.boot/BaseSystem.dmg
4. In Terminal type: open /Volumes/Mac\ OS\ X\ Base\ System/Applications/Utilities/Firmware\ Password\ Utility.app
5. Now you can turn off firmware password - again, provided you know the password you had set

To add a second google calendar on an iPhone where you already set up your first google calendar just visit this url from the browser (safari) on your iphone: http://www.google.com/calendar/iphoneselect

As crazy and esoteric it may seem, syncing your Apple AddressBook to Google really only works when your Mac is synchronized with an iPod or an iPhone. Just plugging such a device and syncing with iTunes triggers the sync to Google. You can also edit a file on your Mac instead to get the same result, as describe on Lifehacker.com:
Change the "Family ID." value to 10001 in ~/Library/Preferences/com.apple.iPod.plist

Thank you Gina Trappani and Josua Ferris!

When restoring OS X from a Time Machine backup (or by any other means) you may encounter problems with Adobe CS applications. When you want to start an Adobe CS app, this message can appear:

'Licensing for this product has stopped working'

This is what Adobe have to say about this know issue:
The Flexnet folders/files required to run Adobe applications can get corrupted, or have permission settings problems, if moved from one machine to another, or through a system restore from Time Machine. Flexnet service licensing failures can't be resolved by re-installating the appliaction, nor will the Adobe CS3 or CS4 Clean Scripts solve this problem. If permissions issues prevented the FLEXnet licensing service from launching, accessing its data, or communicating with Adobe processes, the licensing failure is expected.

The solutions may vary, but your best bet is to delete the following folder:

[hard drive]/Library/Preferences/FLEXnet Publisher/

For more information and further details refer to this document:
http://kb2.adobe.com/cps/512/cpsid_51260.html

Don't bother. Just open the VIDEO_TS folder from the DVD Player.app... Damn :)

mdworker (visible in Activity Monitor) is the Spotlight indexing process (active even though the process is not visible in the spotlight menu).

We had a situation where movie files from a mobile phone (file ending .3gp) caused problems, as the indexer didn't seem to get past them. Using up 99% and more percent CPU which caused the fan to go crazy. Removing the files resolved this CPU madness.

You may find which files could be the problem if in Activity Monitor you click on the mdworker process and the click "inspect" in the menu, then choose "Open Files and Ports".

Even in 10.5.6 Mail still won't place the signature above the quoted text in replies, even if said option is ticked in Mail preferences. The only solution I found so far works, but is sure isn't great:
greate a signature with nothing but hitting return once and check the "place above quoted.." and ake this the default signature.

Good to know (from Parallels knowledge base):

How to setup printing from Windows guest OS using Parallels Desktop 3.0 Parallel Port (Default Printer)

1. Stop your Windows VM if it's running.

2. Open VM Configuration Editor (Parallels Desktop menu - Edit - Virtual Machine)

3. Add Parallel Port Printer to the VM Configuration: click "Add" - select "Parallel Port", hit "Next" - select "Use a printer" - select the printer you have available in the Mac OS.

4. Make sure that you are able to print using that printer from the Mac OS side.

5. Start Windows and try printing some document using "HP Color LaserJet 8500 PS" (it's generic driver that's being used for printing from the Virtual Machine to any Mac OS compatible printer).