I can’t lay claim to figuring this out myself, all credit goes to the guide at Dedoimedo.com, “DirectX in VirtualBox 3.0.0 – Pure joy is here”.

In a nutshell:

• Install a Windows guest under Virtualbox, as you normally would.
• Shutdown the virtual machine, and under Settings – Display, click the checkbox to turn on 3D acceleration. I also pushed the slider up to 128 Mb of video memory.
• Reboot the Windows guest into Safe Mode, by pressing F8 during bootup.
• Install the Virtualbox Guest Additions while in Safe Mode. Ensure you select the optional component “Direct3D Support” during the installation.
• Reboot the Windows guest. You should now have 3D acceleration for programs that use DirectX …

The “Safe Mode” trick was the key part I was missing when I first tried – the Guest Additions installer seems to give no indication that the Direct3d component will silently fail if it is not installed under “Safe Mode”.

One extra issue I experienced, in my case when running Unity3D, was that the mouse was ultra-sensitive, to the point of being unusable, when used in a window displaying 3D graphics. In VMware, this can be fixed by setting Preferences – Input – Optimized Mouse for Games – Always. Presently, I do not know how to fix this issue in Virtualbox.

It’s a plugin that allows simple posting of a Gnome Tomboy note to a Wordpress, Blogger or LiveJournal blog (or anything else that supports the Atom Publishing Protocol). It doesn’t allow setting of Wordpress tags, categories or basically anything else except the title and the body text. But it is a convenient way to quickly get a draft post written and put it on the queue … so if you are already using Tomboy, it’s worth a try.

You can get it at: http://flukkost.nu/blog/tomboyblogposter/
Ubuntu packages at: https://launchpad.net/~hanno-stock/+archive