Following are some of the free SIP account providers that I think worth looking into if you looking for a Free SIP account as noted in my previous article. So go ahead check them out and call some one!
Pulver.com has been providing SIP accounts under the name Free World Dialup, FWD. FWD enables anyone with a broadband connection to communicate over the Internet, whether it be instant messaging, voice, or video. get started here.
Sip Phone Provided by SIPPhone
Sign up here to create an account on the SIPphone network. Once you have an account, you will be able to configure your SIP-based VoIP adapter, or software phone to start making free calls!.
SIP Simple Testbed provided by AG Projects(Really check these guys out)
You may use this free service to register a SIP account that allows you to communicate over the Internet using SIP protocol. You may communicate using audio, video or interactive messaging (IM) depending on the capabilities of your SIP software or hardware device. This a free service with no gurantee and no support. Calling to the PSTN is not possible by using this service. Your account has Presence capabilities based on the latest SIP SIMPLE standards (RFC 3265, RFC 3903, RFC 4825, RFC 4827). You may publish data from multiple SIP devices (using SIP Publish method) and you can manage the policy using XCAP protocol.
OSIP also provides Free accounts via, AntiSIP, company created to provide services around SIP and telephony, also I have known OSIP for a long time. Go here for a Free SIP account.
Once you have a SIP account, you can go to IPKall to get a Washington State Phone Number free.