One-click install:
http://mikie.dy.fi/maemo/shortcuts.install

It installs 9 Home-applets, named ShortCut1 -9

each can be configured individually by editing the corresponding config file: /home/user/.shortcutX.conf

the first line is the application/command launched,
and the second line is the name of the imagefile to use.

The shortcuts can be resized to your need, and the image will automagically scale to fit the entire button.
There is no transparency (yet) this is just a quick and dirty hack.
There is no other way to configure the shortcuts, than to edit the config-files in xterm.
Each shortcut has a predefined function and image, which you can use as starting point to tweak the to your preferences.

Screenshot showing scalability of buttons: