I didn't find such a chip when I last looked, so I've used a counter chip with parallel output and a shift-register to read its output... Is there a reason you can't just use pin2 or pin3 with an interrupt routine?
actually I'm doing this, the problem is to maintain my arduino on and it stays drawing power(the ethernet is consuming >200mA).
I made a research yesterday and comes to this solution you are saying:
1 x 74HC4020 (14-bit counter)
2 x 74HC165N (shift register)
I bought the ICs and are waiting for the tests. I'll put my arduino to sleep, it'll wake-up from a 555 monostable and then I'll have to get the counter, reset it, send using ethernet and sleeping again. My main concern is to get the counter and reset. Do you have any code getting to get the counter?