They certainly do exist, although who knows how you find a good one who knows their stuff. From what I can tell, the only people who still use travel agents are either immigrants who don't use the internet and want someone from their community to sell them flights back home, or the extremely affluent who want someone to put together some type of specialty, luxury vacation package.

Liberty Travel used to have a bunch of storefronts across NYC and places like Philly (although I think they're now mostly if not all closed). You might try their site first to get an idea of options and go from there.