I mean, it all depends on what "better" means to you. Both have WiFi, very good Web browsers, Email, media players, and, uh, make phone calls.
iPhone has Edge and 850 band so might get better reception and will get faster cellular data than the p1i (at least in the US). iPhone has the crazy touch screen, more built-in storage, and the snazzy Apple UI (and logo) all the kids go wild for.
P1i has a real keyboard (albeit a non-standard one ... I liked the m600i keyboard, some people don't), iPhone doesn't. P1i runs UIQ so you'll have more options in terms of add-on software. P1i has what sounds like a much better camera. P1i supports stereo bluetooth, iPhone doesn't.
