I'll use this thread to report some experiences running OpenBox as the windows manager plus desktop environment in Ubuntu on an acer AOD257, which has an intel N570 1.66ghz dual core cpu and 1gb ram, at an affordable $250
The AOD257 is not as easy to upgrade as some earlier acer netbooks (like the AOD250): it can nominally accept 2gb ram in its single slot, but the operation may not be for the fainthearted. I think you may have to do something like (1) pry off the keyboard carefully; (2) unscrew some screws; (3) push off the back panel; (4) flip the machine over and replace the ram; (5) snap the back panel on again; (6) flip the machine over and rescrew the screws holding the back panel in place; and (7) snap the keyboard back on. I'm not quite sure since the acer user guide isn't very helpful, so I'm not in a really big hurry to try the upgrade. Anyway, it's a bigger pain than with the AOD250, which came with 2 memory slots (one empty by default but easily accessible from a little back door)
I put Ubuntu 10.04 on the machine using a liveusb stick; this was a stick I had that already worked. In the gnome desktop, with an active wired eth0 connection, running
only the gnome system monitor on the desktop shows 4 threads (2/core) averaging 50% cpu load overall and about 22% of the ram in use; running top solo shows about 185 processes, 4 active. This, of course, means there's lots going on in the background -- and it's less than ideal because it means limited resources are being sucked bigtime. So we want to reduce the load if possible, and one way to do that is to get rid of gnome and try to put some control of services into the user's hands
From the gnome desktop I installed OpenBox and obmenu following the instructions here:
https://help.ubuntu.com/community/Openbox#What%20is%20Openbox?At the login screen, I now choose openbox from the session menu in panel at the bottom of the login screen. I do some configuration of openbox menus, then launch the gnome system monitor. There's much less overhead: running (as before)
only the gnome system monitor on the desktop shows 4 threads (2/core) averaging about 5% cpu load overall and about 12% of the ram in use; running top solo shows about 155 processes, 1 active
Configuring the openbox menus to get what you want might be a bit of a pain -- but you can still log into a gnome session from the login window if you decide it would be convenient to do that for some purposes
I still have some stuff to figure out