"Back in the day", when memory was expensive and hard to upgrade, there was a common practice of using something called "virtual memory" where a certain amount of hard disk space was allotted to compensate for lower than preferable levels of RAM. It wasn't ideal, but it did help.
Then when Windows Mobile PDA devices really took off (think HP iPac), you could go into stock system settings and decide what percentage of overall memory (say, 64mb total) would be assigned as RAM, and what percentage would be assigned as storage, with 50/50 being the bottom limit. What this said was, when your memory is RAM and your storage is RAM, it's just a matter of semantics, how you choose to divvy it up.
So... why not the iPad? For instance, There is 256mb of RAM allotted as RAM on the original iPad, and, in my case, 64GB of RAM allotted as storage. It should be possible, and perfectly easy, to create a utility that does exactly what the earlier Windows Mobile PDA's could do... Let you decide how you want to allot your memory and storage. Maybe it could work on a stock device. Maybe (probably) it would need to be jailbroken. It doesn't really matter to me.
Unfortunately, all I have found on Virtual Memory for the iPad, is a process, through jailbreaking, that uses remaining ROM (up to 80mb) for swap files. But, this is not a lot of space to be worth the trouble, and tends to crash devices. As I remember from my Palm days, borrowing unused ROM space was NOT the best solution. It's much better to decide that you want to give up a gb or two of your main storage to be reallocated as RAM, as I did with my HP iPac running WinMo 2003. This would be amazing and I know it's not that complex, and has been part of Windows mobile devices for over 10 years.