I was talking to my hairdresser one day about that very issue - how was I, as a 53 year old woman, going to meet eligible guys?
And she said "Go on Plentyoffish, everybody's doing it now"
So, just out of curiosity, I went online to see what single guys my age looked like.
Long story short, that's how I met my oh-so-geographically undesirable boyfriend. Sheer luck, really, when I look back.
My only advice - if you do go online, don't talk a long time before you meet. If you think they're interesting, meet for coffee quickly - odds are, they'll smell bad or you won't click. Get it out of the way. All too easy to develop an online "relationship" and then discover you don't click in real life.