Vemuri got the idea for ReQall after doing research for his PhD, which involved recording everything about his life for several years. "I would not advise doing that anymore," he jokes. "There's too much bathwater and too few babies in there." Since then, he has focused instead on helping users store important information more easily, and figuring out how best to filter it.

Michael King, a research director at Gartner specializing in wireless technology, says that he's impressed by ReQall's focus on context. "There's nothing that I've really seen out there that takes a bunch of these different aspects of context and melds it into a single application," King says. He adds that, while ReQall's service is impressive, assistants of this type will be most useful when they can go even further. For example, instead of reminding a user to purchase tickets, the application might handle the purchase itself.

In addition to the memory jogger technology, ReQall Pro includes integration with Outlook and Google Calendar. The Pro service costs $2.99 a month, or $24.99 a year. Existing users will be able to purchase the service at a discounted rate. ReQall Standard will continue as a free service, but may include advertising in the future.