It would seem to me that if the observable universe has X particles, and each particle has two states, then the observable universe is in one of at least 2^X possible states, since light has had the opportunity to cross from one side of the observable universe to the other (or it could be off by only a factor of two, considering that the observer is somewhere in the middle).

Or look at it from another perspective. My computer has 4GB of ram. That is 2^35 bits, and thus it has 2^(2^35) possible states (huge!) Since my computer is only a small part of the universe, the universe must have a much larger number of possible states.

Nope. It seemed like too trivial a result to try to publish it (though maybe someone has -- I don't know).

> the observable universe is in one of at least 2^X possible states

That's right, but it completely misses the point. Yes, your computer has 2^(2^35) possible (maybe "potential" would be a less misleading term) states, but the number of states that it will ever actually be in is bounded by the number of clock cycles the computer undergoes during its lifetime. If your computer runs at 1 GHz continuously for 10 years, it will have been in at most ~10^17 = 2^56 states. In the lifetime of the universe, your computer will only ever be in a tiny tiny fraction of its potential states.