No idea mate... in wordpress.. it does the pinging automatically! Check the feature list of typepad and blogger to know whether they does it. But remember.. duplicate pings will make you a spammer!
I ping my blogger blog when i make a new blog post. It updates different search engines that your blog has updated.
Why is always the same? OP is expressly asking about typepad and blogger, not your opinions in otehr software he is not using.
Hey Guys, lets share this with you.. http://www.google.com/addurl/?continue=/addurl ..... The best thing to get inside..
Yes you need to.. Pinging help your blog post getting index fast..however, don't overdo or else they will count your blog as a spam blog.
Absolutely, ping away. I like Pingomatic, and Pingler. Social bookmark them too, and get the RSS feeds into some RSS directories. Get your blogs out there.
Don't ping the same url more than one time a day if there haven't been any changes though... mass pinging the same url over and over flag it as possible spam..