You can add this gadget in Blogger blogs, iGoogle page, Google sites, Google documents etc. Pretty much on all sites that supports Google Gadget API.
I have not hard-coded location and link, so that you can change them if you want to promote some other SFD event(like in JFC, for example). Defaults are Birla Planetarium, Chennai and http://wiki.softwarefreedomday.org/2010/Asia/India/Chennai/ilugc respectively.
You can change title too. Since every visible portion is made editable, Tamil Blogs can also utilize this. Just change values in textbox to Tamil when blogger asks you to change defaults if necessary.
To Add Gadget:
Go to the page where you can edit page design (in Blogger this is Dashboard-->Design), click on Add Gadget --> Add gadget by URL and give the above URL. Some services like blogger will ask you to change default values and in others you have to change them after adding by selecting Edit Gadget.