[Animus7]

> For example, say my phone needs to grab some data from my laptop, but rather than have the laptop send all the raw data to my phone and have my phone process it, the system figures out that it would be more efficient for my phone to send code to my laptop, have the laptop process the data locally, then send the processed data back to my phone.

I've been romanticizing this kind of dynamic client-hopping execution in my head for a long time, and I even tried to implement it once. The biggest problem is that it's a provably impossible problem to solve! If your language is Turing-complete, it reduces to the halting problem.

You can make guesses (as Opa does) and cover the simple cases with code analysis, but in practice such attempts have devolved into inefficiency and synchronization problems once you start implementing nontrivial systems over fallible interfaces such as the web. It all brings to mind FGCS[1], and how that just didn't work.

[1] http://en.wikipedia.org/wiki/Fifth_generation_computer

[koper]

What exactly is the problem you are referring to as unsolvable?

[javajosh]

The problem of deciding where best to execute code.