Any way you can...
 

Load all the images, sounds, etc... when you log on the server, so when you go into the level with like, 3 lamps and some more images, you can see them soon as you walk to the level (Like on some sites with Flash). This would improve the "Loading" time between levels, and on a connected map. (Mabey you can just have one big map, like on RPG-Maker2000 or something).

Re: Any way you can...
 

Uh.. or not?
If all the images were already loaded for you when you log on and everywhere you go then you will have the most intense lag possible. Oh and your other idea is stupid to.

no, actually, I think that its quite nice because you can load all the images. The the rest of the time, its all smooth and no lag.

And then what happens if a new image gets uploaded online? Trivial, yes, but it could be problematic. Also, this would give players the opportunity to delete certain images to get them past hard spots on quests. When they entered the level, they wouldn't get the image back, and they could go on their merry way. I don't really like how that might turn out. There must be a better way...