RightSignature, the company that allows you to sign with a mouse, is making a play to serve as a core integration for the Software-as-a-Service market.

It’s a trend we expect to see more from third-party providers that seek to establish anchor positions as agnostic tools for Salesforce.com and vertically oriented SaaS services.

RightSignature is a digital signature company launched last April. The company started as a service for the small business market (SMB) but has seen pick up in the enterprise, which sees digital signatures as a way to save on the costs associated with creating, processing and completing contracts. Competitors to RightSignature include DocuSign and EchoSign.

It’s pretty clear that third party developers are seeking ways to get into the SaaS market. Salesforce.com has an extensive partner program. They call it an ecosystem, a reflection on how third party developers are working with SaaS providers. On the leading edge, Google Wave is seeing budding interest from developers. For example, Twilio is one of the early developers on Google Wave. The company provides a voice API that companies use to build applications for making and receiving calls.

Daryl Bernstein is CEO at RightSignature. He says that they are planning to integrate with a number of SaaS vendors in vertical specific markets. They now have an integration with Freshbooks. They also integrate with Google Docs. When creating a document, users have the option of uploading from their computer or Google Docs.

Vendors know that SaaS services are like coral reefs. We first heard Dave Winer use this term to describe how third party developers have built extensively on the Twitter API. The same trend is occurring in the SaaS market. Companies like RightSignature are developing applications that work in the SaaS ecosystem.

The RightSignature service allows forms to be uploaded as reusable templates. People are directed to a document, such as a lease agreement, that that they sign with their mouse or with an iPhone application.

The RightSignature user interface is pretty elegant. It has a flow that makes it simple to complete the signing of documents through the automation of tasks such as adding initials to each page, a requirement of most contracts. A flag follows the user, similar to a tab on a printed contract that shows you where to sign. The flag follows the user as he completes signing the document. Photo authentication is included so the person signing the document may be identified.

Part of RightSignature’s appeal is in its overall change to the workflow and the efficiencies that result. Faxing contracts can be eliminated. It decreases the need for services like FedEx, which can run $10-$20 per package delivered.

RightSignature costs $14 per month per user. Up to five users is $49 per month and $249 for up to 25 users. Enterprise contracts work on volume.