Ubiquitous e-service is one of the most recent links in the chain of evolution that has characterized the different eras of the internetworking environment. In order to leap the trust barrier for the users to embrace these ubiquitous e-services, we present a collaborative iTrust e-service for exploring proximal collective wisdom in the ad-hoc ubiquitous environment. By highlighting the homophily of e-service participants, these isolated individuals can be treated as a group with proximity. Proximity thus enables ad-hoc e-service participants to contribute their strength for ubiquitous collective wisdom. Simulation outcomes for trust decision quality enhancement show significant improvement over traditional designs. The iTrust e-service makes it possible for users to collaborate with the nearby user groups for establishing a reliable and trustworthy interaction environment. It also facilitates and empowers the potential benefits of various ubiquitous e-service applications.