My employer is onto its nth slide template. Since they are created by professional graphics firms they are huge bitmaps in the background. That sucks from a lot of points of view, but worst of all this isn't resolution-independent and I usually hand out print outs of the slides since I normally give very technical presentations. That means that everything has to be in vector formats, otherwise the detail on the handouts is as poor as the detail on the screen.
There's a lot of work making the OpenOffice template look like the PowerPoint template, but suck less. Replace white bitmap backgrounds with a real background, replace bitmap text with text, replace bitmap lines with lines. Export and crop photos using the Gimp. And so on.
[Aside: if you are asking a graphics agency to design your logo make sure you get the logo in the source vector format, a license to the fonts used, and the Pantone colours used. Without those you are bound to that graphics agency forever.]
Converting the EPS logo to SVG then loading that into OpenOffice actually worked. This took a small amount of manual editting of the SVG, since Inkscape insisted on inserting a background. There's probably some Inkscape secret handshake you can use rather than editing the SVG with Emacs.
The new slides have a funky background, which looks very much like a old 3270 terminal with the Contrast turned to maximum. So it has to be a bitmap background. I use Gimp to reduce the entire slide's background to something which can be tiled, and then look to put it into OpenOffice.
In a complete user interface disaster this is how you set a bitmap background in Impress:
Format | Area (you weren't expecting that, aye)
Bitmaps | Add
View | Master | Slide master
Format | Page | Background. Select Bitmap from the drop-down box and select the bitmap you added previously.
On the plus side, now I've got the new template done, Impress was very good at importing the 250+ slides of networking equipment, maps, etc and applying the new template.
OpenOffice still sucks for network diagrams, the user interface isn't good for a "place and route" approach. I use Dia, export to SVG, and then import the SVG into OpenOffice (there's a nice extension at www.ipd.uka.de/~hauma/svg-import).