Google has it when you Login and use maps you can save the pins and stuff.. I wish they could integrate something that would let you login and you have them saved or not even login since its you own iPhone
Search for the latitude/longitude coordinates. You will need to convert degrees-minutes-seconds to decimal degrees. South latitudes and west longitudes must be preceeded by a minus sign. If you need a decimal lat/long converter, go here: http://www.fcc.gov/mb/audio/bickel/DDDMMSS-decimal.html. I use Google Earth to get exact lat/long using the "add placemark" feature.
Try it by searching for 38.897661 -77.036567. This will put a pin right on the White House. Tap on the blue > next to the pin to add a bookmark, then edit the bookmark to put in your unique name for the spot.
BTW: map widget also allows searches by 3 and 4 letter airport identifier.