it really depends on what deals you have available at this time from both venues. Compare how much the phone will cost online vs how much it is in a brick and mortar store. I'm also guessing u're buying online through an authorized channel, like Cingular's own site and not through ebay
Online:
pros
-some of the best deals are found here. Many phone service companies will even freely admit to this
-if not cheaper price, they may throw in extras like accessories that won't be given for free at a store
-don't have to leave the comfort of your home, drive out of your way, or take a long, winding bus /Metro train
-Most states won't have sales tax charge levied against it
-sometimes there may even be free shipping as a promo.
cons
-shipping can take up to a business week, so if u need it right away, you'll wanna inquire about faster (and more expensive) shipping methods or get it at a store. Keep in mind u'll want to charge the phone for at least 3 hours priorpto using it
-shipping adds a noticeable extra $$ to the phone
-overall more cumbersome to deal with returns, exchanges, repairs. Also gotta package the phone to return thjis way.
retail store:
pros
-get it right away, minus the time it takes to drive to and fro
-get to deal with an actual person with any questions
-returns, exchanges, or troubleshooting done by an actual person
cons
-you save on shipping and handling, but gas has recently gone up average $0.40 per gallon. In a suburban area where u gotta drive further distances to where u wanna go, that could add up to $5 right there (dep on distance, your vehicle mpg, etc.)
-you'll definately pay sales tax
-the store clerks are not always helpful, and worse, may have u jump through more hoops than with dealing through online channels