I installed Farkle on my iPad 1, and when I go into it (this doesn't happen to any other application), it's saying that I am low on memory and should reboot my iPad. That got me to wondering - where do I go to find out what the current memory usage is??

Settings/General/About

Occasionally i get similar messages, quickly double push the home button-this will bring up all apps that where opened in the past. After that, hold down the home button, (all apps start to wiggle)- now delete all the apps shown at the very bottom which have a red minus sign-swipe along to get all of them. This will free up any hogged memory as far as i understand.