By using Gpolygon we can display a path on gmap. You need to just define order of locations(latitude,longitude) in this.
But you have to know How to generate Gmaps in ruby on rails
Create a polygone array #From Sri Lanka to Afghanistan

polyline=GPolyline.new([[7.880794,80.507813],
[22.792388,79.497070],
[29.874945, 69.345703],
[33.757228,65.522461]],
"#ff0000",1,5.0)

Add into your map

@map.overlay_init(polyline)

You will get following output.

To generate google maps in ruby on rails is so easy and simple. I had recently generated a few maps in my projects by  YM4R/GM plugin.
There are few steps that you need to follow to generate simple gmap.
1. Install YM4R/GM plugin in your rails app.
ruby script/plugin install svn://rubyforge.org/var/svn/ym4r/Plugins/GM/trunk/ym4r_gm
2. Copy  the javascripts files from YM4R/GM plugin [...]

Continuous Integration is a fancy term for “run your project’s tests after someone pushes to the repository and notify interested parties if they fail.”

We’re currently in the process of revamping our test suite (which we’ll blog about in the future) and moving servers, so I thought it’d be a good time to re-evaluate our options.

Just a quick note for those of you who have bought our JavaScript Performance Rocks! ebook & DOM Monster package:

Check your inboxes!

You should have received an email with a pre-final copy of the book. It's pretty much content-complete -- but still has a few editor's notes, and needs a couple minor updates (to cover Safari 4 final, for example), and I plan to add a few more infographics.

Basically, there's just a little bit of polishing left. And I didn't want to keep you waiting any longer!