I was storing my text strings in <page>.aspx.resx but I have since found that
if you use a visual designer (datasets in particular) it clears out anything
you manually put in there.

So, I have taken to creating a new resx file called <page>.en.resx, which of
course leaves the problem that if someone who doesn't have their browser set
to english will not get fallback text.

Is there any way around this? This method also has the side effect of
cluttering solution explorer.

Also, if I were to put all of the language text in one big resx file instead
of individual files, I imagine that would be detrimental in terms of speed
and memory usage when a page is requested. Would that be correct?

Any assistance would be appreciated.