simple home network

i am working from home with my wife, both part time and on separate laptops as i am away a lot during the.

We end up working for the same client on separate items - eg she does the VAT and i do the paye. This leads to us having a copy of the client's folder on each laptop but with data out of synch and having to manually back up on a portable HD then synch with the other laptop etc

tried setting up a 'pogo plug' a while back but that failed as the internet connection was not available or requires login all the time, so a bit unfriendly for day to day stuff. Great if you want to share multimedia...

I am looking for a simple plug and play network drive which does not require proprietary interfaces to use it, i just want to see it as another drive in 'my computer'. I would also like to access it via the internet when away.

Does anyone have experience of any like that?

many thanks