I was at your very same point last summer. I looked at an Epson EP-5000 for a backup, but it seemed to me like Epson staff is a bit -humm- crazy about the price, so I bought an Acer netbook w/ 1GB RAM / 160GB HD / 6 cell-battery, all for 250 EUR (but prices have dropped a lot since then).
I then upgraded the memory to 2GB, and replaced the HD by a 500GB a had at home.
Then I installed Ubuntu linux on it.
It was deep slow to run BibblePro or RawTherappe on it, so I took all the pics in RAW+JPEG, and that was it.
As noted on previous posts, pack a mouse
E-500 & E-30;
ZD14-45; ZD40-150 f/3.5-4.5; ZD14-54
Boots & Jacket plus lots of Coke & Powerbars