Unusual Option Activity in Market today

I don't know where else to put this, as with many things financial, I'm not sure exactly what it means. I was trading calls on DIA (called DIAmonds, an ETF that tracks the DOW)up until DOW 14,000 and have been following option activity since. In my admittedly short option trading life, I've not seen anything like this.

Check out the volume on the puts against DIA opened today at various levels for Sep 21 expiration.
Puts on DIA

Now check out the amount of calls placed on SPY (the ETF that tracks the S&P)at the lowest strike opened FridayAUg 25th.
Calls on the S&P

Like I said I'm not sure what the implications are. My first instinct is the calls on the S&P are a hedge agains the Puts on the DOW, but I'm not confident enough in my financial acumen to be sure. Either way someone has opened some BIG bets against the DOW today. I'd appreciate any thoughts about this.

Edit to add this:
I know that people write puts and calls to generate income. I know there are strategies where you offset one with the other to limit risk. I know from watching, that both of these ETF's are some of the most heavily traded and am used to high volume on both.It's just I've not noticed blocks like this on either ETF before, is there anything to be read into it. Advanced notice of FED decision, inside info on anther fund blowup, or is this perfectly normal?
[edit on 25-8-2007 by jefwane]

[edit on 25-8-2007 by jefwane]