My laptop is starting to show it's age. Time for a replacement.

90% of my work could be done on a desktop.
5% of the time, I do need to go to a client and do some work. A laptop is invaluable for that.
5% of the time, I want to sit in my underwear and read websites/my email on Sunday morning. A laptop is very nice for that.

So while a laptop is not FREQUENTLY needed, it is IMPORTANT. But, looking at the price of laptops, I wonder if that's the way to go.

I'm wondering about an External Harddrive? Could you have a desktop and a laptop with nothing but the OS on the local drive but all applications and data on the external? I'd then get a new desktop with the external harddrive. On the infrequent times I need to go to a clients, I take the laptop and the external drive with me. Both the laptop and desktop access the external drive.

I could get a new desktop and backup my developlment to the laptop when going to a client, then put it all back when I return, but that seems to be a pain and prone to error.

Any other ideas?