The first Android phone with push-to-talk walkie-talkie capability will become available from Boost Mobile, the prepaid phone arm of Sprint, on Sunday. The phone, made by Motorola, will be sold only at Boost Mobile stores and at Best Buy. Prices will vary by store; Boost is pricing them between $350 and $400.

T-Mobile’s one-day sale — all its phones are free Saturday — is pegged to Father’s Day, but others may want to look at it. The carrier is waiving the $200 purchase price for the HTC HD2, HTC Touch Pro2 and Garminphone. The deal is good for one day only, Saturday, June 19. Of course, the deal is good only when you sign up for a new two-year contract or add a new line to an existing contract.

Samsung has announced the release of the Captivate, the first in a new line of Galaxy S smartphones with startlingly bright and detailed screens. The Captivate, which runs the Android operating system and will be available through AT&T, is the first to  have what Samsung calls a Super Amoled (for active-matrix organic light-emitting diode) screen. The screen, which is four inches, is indeed so brilliant I had to turn the brightness down to view it comfortably in a darkened restaurant.

As longtime readers know, I think the cellphone industry is one step away from a big-city mugger. Some of its practices are outrageous ripoffs — like how they charge so much for text messages (both the sender and the receiver), even though text messages cost them nothing. Or how the purpose of two-year contract is to sell you an expensive phone cheaply, on the premise that you’ll pay it off over the next 24 months, but once you’ve paid off the phone, your monthly bill doesn’t go down.

Well, the new iPhone became available for preorders on Tuesday and, wow, what a mess. First of all, AT&T is reporting that it is sold out of iPhones. Yes, already. As usual, there is no telling whether that means that (a) the numbers were so massive, not even Apple was ready for it, or (b) Apple knows exactly what it is doing, deliberately underestimating quantities so that it could generate “iPhone 4 Sold Out” headlines.

I just made $101 by removing a small item from my dresser drawer. And if you’ve got an old iPhone, you can, too. Gazelle, a site that pays for used electronics and tech products, says Friday is the day you’ll get the most money for an old iPhone. That’s today.

This week, Apple took the wraps off of the new iPhone, which will be available June 24, and the new iPhone operating system, which you’ll be able to install on older iPhone models. Apple is now calling it iOS4.

Thursday, I wrote about AT&T’s new Internet-service plans for iPhones and other smartphones. Instead of $30 for unlimited Internet use, new customers will be asked to choose between two limited-data plans: $15 for 200 megabytes a month, or $25 for 2 gigabytes. I noted that most people will save money with the new plans, sometimes lots of it.