To Ping or not to Ping
Many people are a bit confused about pinging. They are not quite sure if pinging has any value. Let’s first look at what is pinging.
In blogging, ping is an XML-RPC-based push mechanism by which a weblog notifies a server that its content has been updated.
An XML-RPC signal is sent to one or more “ping servers,” which can then generate a list of blogs that have new material.
Many blog authoring tools automatically ping one or more servers each time the blogger creates a new post or updates an old one.
Matt Cutts of Google does talk about pinging in one of his videos in which he says that if you ping your site through one of the pinging services like rpc.pingomatic.com, your site may get indexed a tad faster.
If your blog is not listed in Google, Google invites you to ping them at //blogsearch.google.com/ping
This is what Google says:
If your blog is not listed in our results, we want to hear about it.
Enter your blog’s web or feed address below and we’ll do our best to add it to our index as quickly as possible.
So pinging is good when you create a new page / post or if you update it. Don’t overdo it though.
Similarly, you can ping your bookmarks also.
As for re-pinging your bookmarks, I am not sure that would have much value unless you have updated them.
A good alternative would be to create new bookmarks on a regular but periodic basis like once a month and then ping those new bookmarks.