I'm in pretty much the same situation as you. Hybrid bike but mostly road riding and wanting to go longer distances (up to about 30 miles now). I've been wearing cross trainers with the toe clips & straps. It's working OK but I think I can get more efficiency with clipless but don't want to lose the option of walking around. Guy at the shop I talked to yesterday said I can get shoes with spd cleats where the cleats are recessed and it's easy to walk around. One shoe that I might look at is the Shimano MO76 mountain bike shoe. Looks sort of like a road bike shoe, but the cleats are recessed. Here's a link:
http://www.rei.com/product/783236