Interface
What are you more comfortable with – buttons or touchscreens? The latter have the advantage of ease of use though a tad difficult to maintain. A button-oriented interface might seem more familiar but tends to be more complicated and time-consuming, especially if one is on the move. Most specialist GPS devices are touchscreen oriented, although this trend has not really caught on in phones (the HTC P3300 is one of the few phones offering GPS on a touchscreen device).

Sound quality
There is no point having a device that offers voice-recorded directions if the sound quality is poor and this is a department where the phones tend to boss over specialised GPS devices. The Nokia Navigator, in particular, has an excellent loudspeaker.

Applications
While GPS may be the chief reason for your buying a particular phone, it makes sense to check out the other features the phone offers. Would you want an office suite, a good browser, push mail, media player and so on? This is again a department where specialist GPS devices tend to lag behind their phone counterparts, even though a lot of them run on the Windows Mobile interface.

All said and done, whether you choose a GPS phone or a specialised GPS device depends on your primary requirement. GPS devices do offer bigger screens and simpler interfaces and are likely to be favoured by jet-setters but having GPS on a phone can save you the trouble of lugging around an extra device. In terms of cost, a decent standalone GPS device will dent your pocket by Rs 15,000 - Rs 20,000.

If you ask me, I would rather shell that out for a Navigator!