Hi Teddy, if you need to move things to the origin very frequently then that script could help a little bit, but for the more typical occasional use it can be counter-productive to install special scripts when the existing tools can already do the job because it just makes more things to keep track of. The regular move command is also more flexible and allows you to move the object's center to any spot you want, not just the origin.

If you do want to install the script though there is some information on how to install them on the FAQ here:
http://moi3d.com/faq#Q:_How_do_I_install_a_plug-in_script.3F

And the CenterAtOrigin script can be found here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=2409.2

- Michael