Recommendations for Length Measurement?

[Vysathi]

So... I had my BRB out, and grabbed some string to try measuring how long he is. For the first time since I have had him, he got really nippy. Nailed my middle finger and then my fore finger on my right hand. Just little thumps-not 'real' strikes. My best guess is that he didn't like the feeling of the string; it probably tickled or was at least a very different feeling.

Does anyone have suggestions on how I could get a reasonably accurate measure of my snake's length?

And no, I still haven't come up with a name I like... if you have suggestions for me to consider, I'd be open to thinking on them. =D