alot of university web sites have great horticulture pages. My mom is now getting a degree in landscape design and she swears by the site that Cornell offers for plants. you should be able to find good traits and characteristics descriptions on that site or any other for help identifying them. of course revvy's pic may be alot easier, just make sure the pear you match is ripe.
Primary: blueberry apple cider
Secondary: panty dropper cranberry apple cider
bottled: I should probably get some of those...
on deck: future brews suspended for the moment :(...