Unfortunately, I am starting to think this issue, at least for now, will inherently linger. The iPad already comes with only 256mb of ram. iOS 4 already took a toll on the available ram. On bootup, there would be roughly 75-90mb of free ram available for the users. For the most part, this is just barely adequate if one does rigorous web browsing, app launching without closing apps, etc. iOS 5 however, takes nearly 35-50mb of extra ram than iOS 4, meaning there is less 30 mb of ram at times. This means that it is actually on par with the iPhone 3G and original(not 3GS) in terms of free ram, which was quite prone to crashes due to low ram. Other devices that have 256mb of ram, like the 3GS and iPod Touch 3rd gen don't face this ram problem too often, as they usually have a little bit over 100mb of ram at their disposal after iOS 5 (more so at iOS 4).
The iPad has to render more pixels than the 3GS, and even the iPhone 4, but it has only 256mb of ram to handle it. The only long term solution I can see is to wait for Apple to hopefully address the issue with a lower ram intensive firmware, possibly 5.1 update later on. For the time being, the best advice I can give is to follow through with basic ram preservation measures, like regularly closing out apps from the multitasking tray, rebooting the iPad at least once a day, and definitely rebooting it before playing, or using a graphic/processor intensive application.
And, if at the end, the firmware solution doesn't come, in my knowledge I don't see anywhere where this problem can go away. The best thing to do then is to just merely sell the iPad, and go up to a device with more ram, like the iPad 2, which can better handle multitasking, and intensive apps on iOS 5.