Memory usage on ipad

At what point will you receive memory warnings on the iPad?

I am at 42MB of usage (not Virtual Memory usage) and I'm not seeing any memory warnings. When would I, 64, 128 ...

I dug around quite a bit and cannot find any detailed information on this. I did find that there are 3 levels of warnings.

Depends on which iPad you mean, although at this time I don't think it's known for sure how much RAM the iPad 2 has. There is no specific point for receiving warnings in any case, but with 256MB on iOS 4, it's somewhere around 70-100MB.