No, there is no way around it. It's a verrrry annoying strategy and I'm not sure it's worth the aggravation it causes to people like me with only a casual interest in pinterest.
Would you look at that! It wasn't there when I posted the original comment.
Not much better now though. Now the bottom half of the screen is covered by "continue/login" overlay and the top third is covered by fixed toolbars, leaving a sliver of peephole for the actual content. They really go out of their way to annoy the hell out of anyone without an account, don't they? You'd think they'd learn a thing or two from Quora's ill-fated experiments.
Hey that's new, or perhaps I didn't see it before, but in that case I'm not the only one. It doesn't make any difference though. The first thing displayed is a login screen, and I'm not about to create a login just to browse some pictures.