Hi is there any alternative to the atmega328 with more Ram ?
I'm not talking about the Arduino mega, but replacing the chip in the UNO...
Regards...
Not that I know of...
A good option is, I think, the ATmega1284. It doesn't fit in the ATmega328p socket, but I think there's enough real estate in the board to place one. I'm about to start routing a board with that chip... when I get the time. 
A quick look at the ATmega product family will show that the 328 is the "largest" chip available in the 28 pin package. So you won't be able to do a drop-in replacement to a Arduino.
Actually, I think the next best option up the ladder (but it won't fit on the Uno carrier) is the 644; I'm pretty sure it is fairly well supported by the Arduino software/IDE as the Sanguino. Something to check out, at least...
Search for my 'hacking the uno" post where I wired up a 644P in place of a 328 on an uno board to take advantage of auto power switching & USB interface. Skyjumper has been doing the programmig, and is about to order PCBs!
We're gonna plop in a 1284P next on the prototype for even more memory. PCB has 1284P (TQFP) package designed in.
As others said, try http://sanguino.cc/
It's what I use and it works great
I'm using it even without arduino software