OK, I will be the first to admit

that I know absolutely nothing about this stuff, but does it seem odd to anyone else that there will have been, within a few days, four (Charley, Frances, Ivan and now Jeanne) hurricanes/tropical storms that have hit the Caribbean and the Gulf coast of the US? Does anyone know whether this is unusual, historically speaking?

OK. I've done a (very) small amount of research, and according to the NOAA (National Oceanic and Atmospheric Administration):

The period 1995-2003 has been the most active for Atlantic hurricanes in the historical record. Since 1995 seven of nine seasons have been above-normal (the exceptions being the El Niño years of 1997 and 2002). “We are concerned that this increased activity will continue in the coming years,” said Jim Laver, director of the NOAA Climate Prediction Center.

Moreover, it predicts another above-normal season in 2004.

Of course, saying that all the mentioned seasons are above average doesn't really answer the question. To do that, I'd have to go do some more research after this year's Atlantic hurricane season is over (sometime in November) and check, say, the number of storms this season compared to storms in past seasons (both above-normal and normal), and then compare the frequency and severity of said storms to previous ones.