Thanks for all the comments so far.
So I found 512MB of Kingston for $56.50 @ googlegear, I'm buying it later this morning.
Options:
1) Add one 512MB stick to the factory 256MB
2) Get two 512MB sticks, and pull the factory 256MB
Questions:
1) I've had my new set up for 6 days. What's a DELL factory stick worth?
2) Is it worth it to have 1024MB over 768MB? I doubt I'll ever use it, but will it make a difference?