Isn't it so that they can't live forever, just curious how many re-writes they can take before they are stuck.
The datasheet says 100,000 for the EEPROM (10,000 for the program flash.)
10,100 that`s only one rewrite per hour for a year
That good for the just swap chip broad , but the surface mount versions may have short life.
I`m for ever reprogramming the flash.
Only 10000?
Hm I might just think twice before uploading the program to my arduino 
Or to put it like this, has anyone ever noticed this happened to their arduino?
I also thought it was 100,000, so that's one per hour for 11 years or so... should be enough for anyone. I guess if we are designing things that need lots of writes to non-volatile memory we should consider writing to a flash card.
10,000 writes to the main flash is a worry though, the number of times I do it 
But I guess a few hundred is what it takes to get a project up and running, 10,000 should last a while. Arduino's are hardly expensive so I wouldn't mind buying one every now and again for on-the-go projects. In an economic sense I don't want them to last forever either - no-one would build new ones for me to buy and keep it all going!
I'm also interested in more data writes and reads - is there an easy chip extension that can do this, a standalone eeprom chip that's easy to wire up and burn from the main arduino?
I2C EEPROM - 256k Bit (24LC256) - COM-00525 - SparkFun Electronics - real big, real cheap, real easy.
Hm, it's kind of a problem that the Mega got a soldered chip. Why can't they make the ATmega chips with more re-writes? 10.000 is kind of low.
Any rumours that a Mega with socket is on it's way?
Am I missing something here? The 100,000 limit of writes to EEEPROM is something to keep in mind, when writing programs. But for the flash, 10,000 is a lot of re-programmings. A lot. and the chips are $5. Five dollars.
You know a generation is spoiled when they are complaining that their $5, 16 bit, 1000k ram microcontrollers can only be reprogrammed 10,000 times.
Yes, and 10,000 reprograms is most likely a very conservative estimation, mostly likely several times that many. I'm sure most of us will have moved on to much newer and more powerful microcontrollers before we have used up all the reprogram limit.
Lefty
Are we forgetting the Arduino Mega here????
It's 65 USD each time the 10,000 is reached. NOT 5$
You know a generation is spoiled when they are complaining
And I thought I was the grumpy one.
Let's all get back to magnetic core memory, you could get 1K (bytes) in only a two foot square frame. You could program them an infinite number of times and they were none volatile.
Let's hope that Atmel have improved their flash since 2002 when we found in tests that the flash would only take 250 rewrites before failing. Mind you in those days they didn't quote an actual figure they just said "thousands"
Any rumours that a Mega with socket is on it's way?
100pin TQFP sockets cost about as much as the whole MEGA board.