I believe the term originated with a song by singer-songwriter Christine Lavin. I first heard of her song in the early 90s.
A writer over on Article Base, Raiha_Evelyn wrote her own 10-step program to becoming a SNAG.
There's also an article over on askmen, but there's too much junky stuff in the margins to link it here. The article actually was pretty entertaining, as far as I read before the kids came in the room. Yes, that kind of marginal junk, not even "marginally" appropriate.
One of the Urban Dictionary's entries defined a SNAG thusly,
So, since there are not really many articles I can link, and even the videos of Ms Lavin's song are not really that great...I'll just link her lyrics in here and stop tryng to be interesting.Sensitive New Age Guy (S.N.A.G). Similar to the Metrosexual, but more timid and sensitive. Dense clusters of Snag's can be found at woman's issues rallies. Extreme examples have been known to experience regular menstrual cramps.Phil Donahue (extreme example)
But I will say that she doesn't mention pedicure's in her song, I think you're safe, my friend.