Ibook G4 memory

I have a fairly new 14" ibook G4 with 512 mb RAM. I have noticed that the last while if I have a few safari windows open and each is opening a site (on dial up) the ibook tends to hang a little and I get the little coloured wheel telling me its working.
Should I get more RAM to cure this. I am also doing some home movie editing and was wondering do I need more than 512MB. I was thinking about getting another 512mb or do I need another 1GB.
I read somewhere that the biggest bang for buck was adding 512mb and after that the improvement was minimal, is this true?

I cant answer the second part of your question but the reason why you are most likely getting the beachball is because your RAM is congested. Are you using any other programs while your using safari?...Think about it as a 4 lane highway. Two lanes going north and 2 going south, sometimes it will get congested. If you get another 512 stick then you are going to turn the 4 lane highway into an 8 way highway and information will travel fasted and more efficiently.

Are you using Panther 10.3.9?

I have an ibook 1.2 with 1.25 GB RAM and Safari does the same exact thing. Even when Safari is the only thing open, it has delays.

I have 2 thoughts on this.
1 - this is how safari 1.0 is. I see it on my eMac 1.42 with 1GB RAM as well, though not as bad. Safari seems to be really straining the CPU when it happens. .
2 - The hard disk on my iBook is pretty full, with not much more than 5GB available out of 30GB total at any time.

RAM is definitely a good thing, but I think the specific issue here may be hard disk speed / access time. I've thought about forking up for a 7200rpm 2.5" drive, but I think I'm going to wait for the Intel iBooks. FireFox and Camino are really quite a bit quicker on the draw than Safari 1.0, so I really think the root problem is something about the way Safari 1.0 works.