Hello All I've posted a list of Pinging Services on my blog over here --> http://www.websack.net/2008/12/14/list-of-pinging-services/ My Blog is a DoFollow Blog! So, comment on my blog as well as here! Thank you!
Should i use all these, or just the one in wordpress as standard, is this not over doing it? does it cause any problems in anyway?
It will cause problem if you keep pinging only one Search Engine over and over. So, just submit to each of them only for once or twice and not more than that! Don't do it more than twice per day
You've got to be careful. Many of these aggregators ping the same services. This may cause some of them to mark your blog as spam if they get pinged multiple times in short succession.
If you use Wordpress you might be interested in this plugin MaxBlogPress Ping Optimizer. (not an affiliate link) I have just recently installed this plugin on my sites so I haven't any stats to prove if it works (not sure if there is a way?) but it makes interesting reading. I recommend his plugins and use most of them.