Well first off you guys, I really like your pictures and the imagination being shown, it is surprising what you can achieve artistically just having a mess about with a few pictures. You really can liven up a few run of the mill images and use up a lot of your spare time as well,

but what the heck, it is winter and not a lot else to do other than watch TV.
By the way Grandad, they only say 512 MB is needed, but recommend 768 MB if using Vista and a processor speed of 1 GHz with 2 GHz recommended. My own desktop exceeds those requirements, but I find it does hog a lot of resources when running, no problems as such to report though.
LLL, regarding the 'tablet' thing (you say palette), if I were you I would seriously consider going out and buying a USB standard mouse. They are very cheap and you will get one for less than £10 that will be perfectly suitable for your needs. I say this because I don't think that you will be able to work very well just using the laptop pad, well at least I know I couldn't. They just don't have the sensitivity for doing this sort of artwork where you are using repeated moving and clicking to perform various tasks when editing your pictures, I think you will find it very laborious using a touchpad.
As to the 'tablet' well if it would still work with the program I may be tempted to use it on occasions, but to be absolutely honest, the ability to use a 'freehand' pen to work around objects and to select them, has in my opinion been overtaken by the programs themselves making these tasks easier to do than was previously the case when using a mouse.