I have found multiple times the reuse of photos when using dating sites.  If you see a photo that you recognize that isn't going by the same name as what you saw before chances are they are a scammer.  Also multiple profiles with this picture or pictures that profile is a scammer's.  I have found that it really has nothing to do with how many pictures one has but really whether they are real or not.

Another interesting thing is if you cut and paste their bios and search google with the bios if you get something on a totally different site with a totally different girl then they are scammers.  And real girls you should do this with the guys you meet too.  I was on yahoo personals and some girl sent me a message and I found the exact same description on another profile that was in the message with a totally different girl.

Also most likely if they use words like "tender" they are scammers.  That type of word makes a guy have crazy thoughts.

If you talk to them on Yahoo IM and they give you any form of site they are scammers.

Hope this helps... :-)

I will find more stuff to watch out for...