I guess I need to take this racing thing more seriously. I always viewed it as a means for the local clubs to get money. None of the venues I sail (except Miami-Key Largo)have a pre-pay option, although some have pre-register (via web). On that note, the pre-registration thing seems to be quite a motivator to get more people in your fleet to show (since they'll see that there are enough to make a seperate start/scoring).
Again, IMHO, the pre-reg. seems to be an adequate compromise to the pre-pay vs. on-site debate. Gives the organizers more of a head's up on getting the logistics right.
I've been to a few events where the weather was just plain "too nasty" to sail. In one event, we just all took over a local bar and played video games, slurped oysters, and "contributed to the local economy" (as well as the AA chapter, but that's another story...).
With respect to events with bad forecasts, I still paid (in the hopes it would clear up by the next day), or didn't ask for a refund because I see it as sort of a "donation" to the club. Besides, the entry fees are not that outrageous, and if it keeps the club/volunteers/organizers motivated, all the better for me next year. Sure, I'd rather be racing, but as a friend and competitor said, "the weatherman only makes you want to cancel. No one ever saw the weather and said - well, I wasn't going to go before... but I will now..."
And to agree with Mary - sailing in less than ideal conditions certainly helps your skills - either sailing, or repairing!