You have 1GB of RAM, which would not be affected by a flash drive, or anything else that isn't a stick of RAM. Technically, you would be adding 2GB to your computer's 60GB hard drive, but this isn't completely accurate, as you wouldn't be using that space to install anything serious on. It would be acting as temporary storage for files. You can put whatever you want on memory cards from digital cameras, with the caveat that your camera won't be able to run documents or other such stuff you throw on there from the computer :].
If you are looking for increasing RAM, you would just have to buy another stick of it. Depending on what you use the machine for, though, 1GB of RAM might be all you need. I wouldn't worry too much about it, and just see how it performs for you.
Also, keep in mind that laptops will not always have an extra slot for RAM, and being that the Inspiron 12 is sort of a macbook air clone, I wouldn't bet on it. Sort of odd that they opted for relatively modest hardware for a vista machine. Still, though, I wouldn't worry about RAM too much, nor your HD space, given that it IS supposed to be a light laptop (that is, unless, you are a hardcore gamer and photoshopper).