While building, it's fun to "dream the dream" of the various "Internet" engines (that exist mainly on a web page somewhere), but when you start seeing the light at the end of the tunnel and you begin to see that you're closer to that first flight, it's usually time to snap yourself awake and order that Lycoming.
The Internet engines are fun to watch, though, and imagine what people "might" be flying long after our generation is gone.
Personally, I'm still watching this guy who I think has a better chance of success at his project than does some of the other Internet Engines.
His goal certainly does seem to give him much inspiration and perseverance.
http://www.asciimation.co.nz/beer/