Can you FOREX trade with Multiple currencies?

[Stan]

Hi,

I hope someone can answer this for me. Is it possible to trade using
multiple currencies online with any of the online traders? I.e.

USD -> EUR -> GBP -> USD

Instead of the traditional way

USD -> EUR -> USD.

If you can trade multiple currencies, does anyone know how? What
companies provide this function online and are there any programming
API's that do this.

Any help would be greatly appreciated.

Stan