A new website called UFO Maps combines UFO reports with a Google maps overlay. The website puts little clickable UFO icons on the map to represent where a UFO report took place. You can click on the UFO icon to learn more about each UFO report. There were quite a few reports in September primarily in the Midwest, which looks like it is being invaded. As UFO Maps points out Wikipedia's UFO entry lists some of most frequently reported characteristics of UFOs.
Saucer, toy-top, or disk-shaped "craft" without visible or audible propulsion. (day and night)
Rapidly-moving lights or lights with apparent ability to rapidly change direction — the earliest mention of their motion was given as "saucers skipping on water." Disc-shaped craft are sometimes reported to move in an irregular or "wobbly" manner at low speeds.
Large triangular "craft" or triangular light pattern
Cigar-shaped "craft" with lighted windows (Meteor fireballs are sometimes reported this way)
A new website called 
