I've tried to install
banshee-extension-soundmenu which isn't available in my 10.04 repos, so I did some research but couldn't find a repo that offers it for my Ubuntu version.
How can I install it and get the wonderful buttons into my sound menu?
The new Ubuntu sound menu, which lets audio players like Banshee add album art and player controls to the menu, was introduced in Ubuntu 10.10, so this functionality isn't available in your version of Ubuntu.
The closest you can get to the sound menu extension without upgrading Ubuntu is probably the banshee-extension-appindicator, which is available in the 10.04 repositories.