If you don't fancy carrying the delicate Ubuntu installation CD around with you, you can copy its contents to a USB key stick and use that to install Ubuntu onto computers (provided those computers can boot from USB, and most modern computers will be able to).
If you opt to share folders across a network under Ubuntu you'll find they're protected with your username and password, which you might not want to share with others. The Shared Folders dialog box allows you to setup guest access but, at the time of writing, this had a serious
bug that rendered it unusable.
Several of my computers sometimes mysteriously lose minutes when switched off, so that the time they display slowly becomes more and more behind. Luckily I have Ubuntu installed. This can periodically synchronize with the main Ubuntu time server, and thus never let the computers get out of step with the rest of the world.
Both the color scheme and font of GNOME Terminal can be tweaked. This can be a good way of improving legibility and also the amount of space GNOME Terminal hogs on-screen, because a smaller font size makes the window smaller too.
If you've got a notebook computer, you might be used to edge scroll on the touchpad when running Windows. This is where the right-hand edge of the notebook's touchpad is used as a virtual scrollbar - by running a finger up and down, the currently active window scrolls up and down correspondingly.
Most fonts contain within them "hints" laid down by their designer about how they should look on-screen. However, Ubuntu ignores them and uses a system called autohinting, which improvises the hints based on the shape of the letters.
Sometimes if you're trying to help somebody fix a problem you'll have to tell them how to install software. Yet for some Ubuntu newbies even this can be confusing. The solution is to create a "software install" hyperlink within a web page (such as a forum posting), new email window or Pidgin message window.
It's a myth to say that Ubuntu (or any Linux) needs a swap partition. This is certainly the preferred way of working, and is most efficient, but Linux can also use a single swap file located in the root partition, just like Windows or Mac OS X.
While Zip is the main compression file format used on most desktop computers, some people prefer to use the RAR format.
Gedit shouldn't really be used for printing stuff out. That kind of thing is better handled by OpenOffice.org. But if you occasionally run off a quick block of text, or look at hard copy of some code, you'll havenoticed that Gedit always prints in Monospace font, even if you've set the screen font to something else in Edit → Preferences.