Is there a benefit to ping your URL's from websites like http://www.pingmylink.com/ this ?

Well, Pinging doesn't adds any value to website's rank-ability in Search Engines but it does help search engine Web crawlers to discover content quicker that is required to attract traffic.

its benefitial for the websites and SEO. Google know about the updates on the site due to the ping. The main goal is to increase the probability of your website getting index by bing , Google and the likes.

the best way to submit to a search engine, is via the search engine's webmaster utilities.
google (important) bing (useful) ask (ok) and yahoo (who gives a f###) have webmaster pages

second best, is infinitely better than not at all

URL pings means sometime website not showing and display error also that need to finging error.

Kelly Burby! First thanks so much... Second, I just want to get a clear conception about this brief

"Using the Ping services is a way for you to inform the search engines to Index your newly added or updated Blog post pages into their database.
As a result of all this search engines are able to count your blog back-links quickly, which in turn is useful to your site ranking; besides Ping is also helpful to your blog SEO. Pinging sites are used to complete your blog indexing process quickly."

Is it contradicts from what you thought?