Note: I am in no way related to the development of this application, but rather am sharing it with others as it is a great addition to "Lion" in incorporating "Snow Leopard" Spaces (and soon Exposé features). I posted this in another thread as a reply but thought a new thread would garner more attention for those who desperately want these features in "Lion". 
Download link:
ReSpaceApp
It is still in beta stage and is free. Here is the list of current features and upcoming features:
Current Features
- Navigate a grid of desktops using hotkeys for each direction
- Use the transitions, hotkeys and navigation preferences you desire
- All accessible from a handy icon in the status bar, that also indicates your current desktop
Coming / Requested features
I take requests for features over at get satisfaction. Although I can't promise anything, I will do my best for any reasonable feature requests. Below are things that have been requested, and that I think would be good to add. Again, I can't promise by particular dates or versions though.
Full screen apps
Although ReSpaceApp partially supports full screen apps as of v0.9.5, it is intended that they can participate more fully in the grid of spaces, in particular by being visualised in the select grid view, and with more options as to how they can be navigated to.
Multi monitors
The select grid should show both (or all) monitors' contents, not just the main screen.
App window dragging
Windows should be able to be dragged from desktop to desktop via the edges of the screen.
Dragging windows between desktops in select grid
Windows should be able to be dragged from desktop to desktop in the select grid view.
Locking apps to desktops
Although you can lock an app to a desktop using the ctrl-click menu from the icons in your dock, this is very fiddly, and we wish to bring control of which app resides where inside the preferences of ReSpaceApp.
Naming desktops
Right now the system names your desktops for you, but it's nice to name your own desktops.
Gesture support
Changing space with gestures.
Mountain Lion
My crystal ball says it should be possible to support Mountain Lion. I won't start taking payment for ReSpaceApp until I confirm this.
Download link:
ReSpaceApp
It is still in beta stage and is free. Here is the list of current features and upcoming features:
Current Features
- Navigate a grid of desktops using hotkeys for each direction

- Use the transitions, hotkeys and navigation preferences you desire

- All accessible from a handy icon in the status bar, that also indicates your current desktop

Coming / Requested features
I take requests for features over at get satisfaction. Although I can't promise anything, I will do my best for any reasonable feature requests. Below are things that have been requested, and that I think would be good to add. Again, I can't promise by particular dates or versions though.
Full screen apps
Although ReSpaceApp partially supports full screen apps as of v0.9.5, it is intended that they can participate more fully in the grid of spaces, in particular by being visualised in the select grid view, and with more options as to how they can be navigated to.
Multi monitors
The select grid should show both (or all) monitors' contents, not just the main screen.
App window dragging
Windows should be able to be dragged from desktop to desktop via the edges of the screen.
Dragging windows between desktops in select grid
Windows should be able to be dragged from desktop to desktop in the select grid view.
Locking apps to desktops
Although you can lock an app to a desktop using the ctrl-click menu from the icons in your dock, this is very fiddly, and we wish to bring control of which app resides where inside the preferences of ReSpaceApp.
Naming desktops
Right now the system names your desktops for you, but it's nice to name your own desktops.
Gesture support
Changing space with gestures.
Mountain Lion
My crystal ball says it should be possible to support Mountain Lion. I won't start taking payment for ReSpaceApp until I confirm this.