I would like to set up Gnome in a similar way to how I use iceWM with rox.
With rox one can use the commands:
rox-filer --pinboard=PIN
You then drag and drop apps from rox onto the new desktop pinboard supplies.
Further desktops are:
rox-filer --pinboard=PIN1
rox-filer --pinboard=PIN2
and so on. The desktop icons and backgrounds are then replaced by the pinboard.

Each of these can then be applied to a launcher and one can have different desktop layouts at the press of a button.
When I tried this with gnome, it keeps dropping back to the nautilus desktop. Unloading the Nautilus desktop seems to be the wrong way to go. It would be preferable to use naultilus itself to swap layouts if possible. Is it?

Are you saying you would like different desktop icons and backgrounds with each workspace? It's not possible with Nautilus, at least natively. We were just having this discussion:
http://gnomesupport.org/forums/viewtopic.php?t=8848

No I simply mean alternative layouts that can be switched with a simple command that can then be assigned to a taskbar icon like one can do with rox pinboards like I descibed.

Sorry, I misunderstood you. I do not know if this is possible. Not sure if anyone at Gnomesupport can answer the question - I have never experimented with what you are describing before.

GNOMEs not very flexible in terms of customisation so I doubt what you want can be done. Anyway you could ask on the various GNOME mailing lists or IRC to find out if its possible.

Thanks guys. I have to admit this lacking in customisation options with Gnome is the main reason I tend to use other desktops. Oh well each to their own I guess. I may pursue it further when I get some time and if I do suss it I'll post the results.