Onlywire is truely an auto submission service. It will allow you to bookmark sites in sixteen different places with one account. Once you create an account with OnlyWire you then add your login information to various other services. After your account is created and you update your logins then you have to only submit sites in one place for it to be bookmarked in all of the services they support.
SocialPoster works a little different than Onlywire in that it does not automatically autopost to other accounts. What SocialPoster does is allow you add links, tags and comments then populates a list of 42 different bookmarking sites for you to manually submit to. It is more work than OnlyWire however it does support more sites.