When I bought my i9000, there was a task manager kind of thing on the home screen which showed a memory status bar and the number of processes, and when I touched it it showed details of all process and active applications. I deleted it but changed my mind. How can I get that widget back?
long press the home screen, select samsung widgets--> select program monitor
I think the "Task Manager" app was available from the Samsung Apps store in Android 2.1, I seem to remember downloading it from there at some point along with the "My Files" app. You can try going into Applications list on your phone, finding the "Samsung Apps" icon and looking through the list in there.
If your phone is running Android 2.2 then the Task Manager is "built-in" and is not easy to delete. You can see if it is still there by holding down your Home button for a few seconds until the recent apps list comes up, and you should have a TaskManager button at the bottom.