Sometimes it's just fun to see how far...
http://home.comcast.net/~buck0/outpvccm.html
This link brings you to a collection of e-mail exchanges outlining the
construction of a collinear 5/8th-wave 2-meter vertical. Insights,
discussions and inovations on 2, 3, and 4 stacked elements. Several great
images too.

Special thanks to Paul Anderson N8CVW /7. He took some ideas I played
around with (and posted on the WWWeb over 6 years ago) and really went
hog-wild!!
http://home.comcast.net/~buck0/5-8thx2j.htm

Hope you'll see there is still some fun to be had in the hobby, in the ways
of antenna modeling!

73
Steve KB1DIG