Transparentshow alternative?

[pgtipsy]

Is there any alternative for Impress to the transparentshow add-in for PowerPoint? If not is it possible to create one / have someone create one for me?

I desperately need the ability to show a portion of the desktop (and in some cases other programs running in other windows) below a presentation, from within a presentation. As far as I can see there is no way to have a transparent background without an add-in.

I would greatly appreciate any help anyone can give me with this.

Thanks.