While several research projects have been proposed to use software agents to deal with information overload, their results are not applicable in the existing Web infrastructure mainly because no Web sites are agent-enabled. There are two main reasons why Web site operators are not willing to let agents run on them: (1) security issues; (2) many commercial Web sites make money from advertisement, and if agents are going to do the work then who is going to see the ads? In this paper, we discuss the design of an architecture that addresses the above issues. What is interesting about this architecture is that it enables businesses to form beneficial partnerships (e.g. between content providers and Internet Services Providers (ISPs) or even cellular network operators). A proof-of-concept implementation using Java RMI for this architecture has been carried out as part of the Havana mobile agent platform. This platform can be easily integrated into existing Web sites, and accessed from any device.