Looking in the market, found this app and it looked pretty cool. Same app, just slightly different name for paid vs free.
Free: (no widget)
Paid $0.99 (widget)
Memory utility that seems to dig a little deeper than some I've seen. Both versions let you see what processes are running, but what's different on this app is it lets you see how much memory that process is actually using, as well as the total amount of memory that is allocated to that process, and what the priority is.
I've been using it for a few hours, and I've noticed if I have it running, if a process becomes completely dormant it will tell you "This process is empty of any actively running code." and give you the option to kill it. So that was pretty cool I thought, that it told me when something needed to be killed. I've only seen this when I was actually in the app though, not when running the widget which is good as that would seem intrusive and annoying (see Vista, lol).
The 2x2 widget is also more detailed in stats than some others. It tells you how much memory is available, how much is in use (Active), and how much is allocated but not in use (Inactive). It's got a refresh button, so just click and it updates very quickly. I think it gives you a much better view of how your memory is being used, and I'm really liking the widget a lot.
Also, I had been running the TasKiller taskbar widget which reports available memory, and this app/widget is 100% spot on with what that widget was reporting. I can't comment on battery life or anything having only had it a couple hours, but I'll come back and report on that and other impressions later.
Here's some shots of the app: