Looking for a better desktop calculator? sudo apt-get install qalculate

The Ubuntu desktop includes a very basic calculator. But it's exactly that - basic.
In contrast, Kubuntu comes with KCalc, a definite step up from Gnome's default 1+1=2 calculator.

Ubuntu One is a sharing / storage / file-syncing service provided, both, free and commercially, by Canonical, Ubuntu's corporate sponsor.

As great as this service is, and in those instances where nothing you've tried seems to work, here are the instructions for re-installing Ubuntu One, via command-line, as provided by one of the UbuntuOne devs, in this UbuntuForum thread - ...

Stopped in for a visit at my sister's house last week and decided to check out her brand-new MacBook Air. I was pleasantly surprised when I opened the lid to discover that Mac's OS-X looks very much like Ubuntu 10.04 - Lucid Lynx – or vice versa.

Turns out there's also a cool little project called Macbuntu. The aim of the project, as the name suggests, is to make your Ubuntu desktop look and feel like a Mac OSX desktop. - Very cool!

Use Alt+F2 to launch applications

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Scanning the Ubuntu-Forum for new posts this morning, I found a thread about missing Panel icons.
The author of the thread was stuck because he'd lost his panel icons for whatever reason and couldn't figure out how to restore them.

Karmic Koala featured a 60 second logout confirmation dialog. Everyone hated it, so the devs took their vengeance by putting in a logout-confirmation dialog that's worse than Karmic's – Lucid Lynx's has no timer at all – the confirmation pop-up will sit there all day waiting for you to confirm that yes, you really meant to shut down the computer!!!

Contrary to popular belief, the fix is easy...

Press Alt+F2 to start the Run Application launcher, type in gconf-editor, scroll to apps, then indicator session, and put a check-mark in the suppress_logout_restart_shutdown check-box ...and you're done.

Easy-Buntu.

The simplest way to speed up your Ubuntu desktop is to use Alltray.
Alltray is a tool you can use to park applications in the tray – that's the area of the panel where the volume controls and network applet reside.
The effect is "instant-on" applications.

Ubuntu is Linux, and a such it's inherently fast. The single slowest point of any Ubuntu desktop is the launching of applications.

On my P4-era laptop, Evolution, the default mail application, takes 4 to 5 seconds to launch. Alltray eliminates that launch delay, and docks the application for instant recall. – Admittedly, compared to the current Multi-Core processors found in newer computers, P4 is starting to get a little old. If you're stuck with a P3 or P4 however, AllTray will bring some snap back to your desktop.