(Haven't read most above comments) How about no trains for a challenge? A lot of the pictures I see are trains, which are cool but it would force people to be more creative if that wasn't an option.
Hmm, I personally quite enjoy seeing the trains, so I'd have to vote against Though, indeed, I don't always pick the first picture, sometimes I search for quite a while to find a good one. Also, can you post 3837? (I want to do 3838 )
(my page refreshed, got to retype <.<) Nah, trains are cool. Perhaps a rule where we can only do trains? I try to pick the most interesting picture from the Google results, preferably one that isn't similar to another recent picture, optionally looking up a higher quality picture. If I can't find anything I like very much I might look for some more precise terms, but those don't always turn things up with such high numbers. Often I prefer the train though, when the other pictures are Simplity, Lego and Playmobil sets I don't find all too remarkable. Especially when the train's different from most recent trains.
We may have got this game, but I don't feel like looking for it so here's a picture I picked from Google.