Is the "double geometric" payout method for pooled mining fair to part time miners? The "double geometric" payout method as used on the Ozco.in pool is supposed to be fair and prevent pool hopping, but is this method fair to miners that only mine for a few hours per day, as opposed to miners that mine 24/7?
Yes. If you mine at a given point in time, you do not know when a block will be found, and thus your reward for shares you submit is a random variable. DGM is constructed so that the average reward for a submitted share is always equal to what you would get from it in PPS (assuming equal fees). The total reward for all shares you submit is additive - so it follows that the average reward you get in DGM is equal to what you would get in PPS, no matter what is your mining pattern.

However, the reward you will get is random and has some variance, and the variance is greater if your mining is intermittent. The exact degree of this depends on the parameters used by the pool.

More background information about mining pool reward methods can be found in Analysis of Bitcoin Pooled Mining Reward Systems.