Digital Flash Card Help--Toni or anyone in the know?

I have an older model Canon digital camera, the PowerShot A20.
I am looking to get a larger flash card. I have a 128MB but want either a 256 or 512MB(San Disk brand) for a wedding I am doing "informal" photography for....
Does anyone know if those cards will fit my PowerShot A20? I read reviews on the 256MB at a site that has a GREAT price on it and these reviews came from people with more recent models of PowerShot cameras. They said they worked fine but were a tight fit in the camera.
Are SanDisk compact flash cards universal...do they fit all PowerShot cameras no matter what the MB? Because my camera is older, the highest MB they have listed in the instruction book is 128.
Anyone know a good camera message board I could go to for help on this?
I've tried some searching on my own but am not coming up with anything to help me.
Thanking you in advance for any help you may have for me!

I know very little about digital... and my powershot bit the dust over Christmas

this site might help: http://p207.ezboard.com/bphotographic5785

Thank you, Toni! I'll check out the site you suggested. I am a terrible searcher on the net, I guess I choose the wrong words or something....I tried to find a photography/camera MB and the few things that came up, I couldn't find any links anywhere to take me to an actual discussion forum! :scratch:

I've been a member of Photographic for about a year now and this is a very nice board... you can get a lot of great info by asking questions and showing off your work

I ordered and rec'd the 512 MB flash card and it fits and works in my camera just fine! Now I shouldn't have to worry about running out of "space" when taking pictures of special events!