Power from switching AC, Vin and USB ?

Hi, I'm exploring the alternatives to power up my arduino 2009 based application. Everything will be 5V so I would like to connect everything together to the same power source. My initial estimates of total current are around 2A-2.5A.

I was thinking of supplying the arduino through the 'Vin' pin, but then I'm affraid of plugging the USB cable for programming.

Someone sugested cutting the 'power' wire of the USB cable. Do you know if this is hard to do and if I can buy a cable with no power wire? (lets keep hacking to a minimum ;D)

Also do you know what is the voltage tolerance of the arduino? +/-10% ?

Last question: Can I use a switching power supply (like Playstation Portable AC adapter which is 5V 2A I think) instead of building my own regulated one ?

http://en.wikipedia.org/wiki/Switched-mode_power_supply

then I'm affraid of plugging the USB cable for programming.

Depending on what model of arduino you have the power is selected either by a link or automatically switched over. The automatic type depends on feeding the power through the Vin direct to the +5V. What model do you have?

Also do you know what is the voltage tolerance of the arduino

Maximum of 6V (absolute max don't think of exceeding 5.5V) it can work down to 2.7V although not at 16MHz.

Can I use a switching power supply

As long as it is DC out then you can use any sort of supply / adaptor. However if you are going through the Vin it needs to be about 7.5V for the regulator to work, otherwise if you are feeding it to the +5 line you just need 5V.

What model do you have?

Arduino Duemilanove with ATmega328P.

However if you are going through the Vin it needs to be about 7.5V for the regulator to work

My mistake, I was thinking about the +5V pin. I need to bypass the regulator because it would get too hot with 2A.

Someone sugested cutting the 'power' wire of the USB cable. Do you know if this is hard to do and if I can buy a cable with no power wire? (lets keep hacking to a minimum)