The interested visitor (hello!) should read through the blog posts and comment boxes of two Catholic converts on this matter:
I don't think it was ever drilled into me, a cradle Catholic, that non-members were damned as such. For example, there are those Catholic doctrines on baptism of desire, baptism of blood (martyrdom), perfect contrition, etc. I never heard Sister Martha, Father Joseph or any of our teachers point out "those wicked [insert least favorite religious group here] are damned because [insert favorite rant here]!"
Catholics who think that non-Catholics are necessarily denied salvation are probably the same people who think that Catholics are necessarily saved, and both are wrongheaded notions.