I did jail break iPhone 4 with iOS 4.2.1 ipsw by newly released PwnageTool 4.2.
It works fine.

Thanks dev-team for so much effort.

3G still could be unlocked untethered JBed with iOS 4.2.1 ipsw + ultrasn0w. I want complete unlockable untethered JB tool for 4.

I found my iPad by "Find My iPhone" of iOS 4.2.1. (not iPhone on the leftside image though)

I tried to register my Apple ID which I regiesterd before, but registration program rejected like already existed address. It was so inconvenient that I had to create another Apple ID only for me.com.

Beejive is multi protocol IM (Instant Message) client for iPhone. Most of iPhone users use Fring because of its price (free), so no one takes care of 1,200 yen app for IM.

I guess I wouldn't have paid for it, if I did not need look for an app which could run / connect in background and supported Jabber Group Chat.

There is not any better app for Jabber Group Chat than Beejive. This app is so stable and use less battery. It is worth to pay 1,200 yen.

I reported so late, but I should say this is the best combination of digital gadget ever, MacBook Pro (Core i7) + iPhone4 + iPad.

Before Core i series, MacBook Pro reached at only convinced level as a note pc for Pro/Prosumer's demand. Then, at last, with Core i series (especially Core i7), MBP became truly Professional note.

Like MBP Core i series, iPhone4 also got a power to be a real smart phone / PDA. I think 3G and 3GS were just a experiemental products of Apple for the next generation of real products. Honestly I say, 3G/3GS were good gadget, but it was sucks level for daily use.

iPad is a innovative product for living room and eBooks, though iPad won't be completed until iOS 4 for iPad is released.

MyWi is iPhone application which creates wi-fi hotspot on iPhone and enables tethering through 3G network.

I had already been aware of this app when Cydia alternate app directory "Rock" was released, but it didn't work well on my iPhone at that time.

I tried it once again, and now it works so fine. As its developer said, it seems work faster than PdaNet because of using native routing process, and it uses less battery resouce than PdaNet.
It supports also USB and Bluetooth connection.

MyWi is so nice app that it's worth jailbreaking.

I think WEP should be upgraded to WPA2.

By Dev-team's so much effort, JailBreak and SIM unlock was succeeded on iPhone software 3.0.

New SIM unlock app for 3.0 "Ultrasn0w" works fine with SIM card of NTT DoCoMo.

Most of apps which I need runs smooth, but I forgot to uncheck Pineapple logo of QuickPWN. Anyone knows how to change boot logo without restoring again? "LogoMe" can not be installed and does not run correctly in 3.0.

Boot logo image seemed to be loaded from flash ROM.

Ustream.tv is a web site where you can broadcast your video and watch videos broadcasted around the world.

They released Ustream client for iPhone. It stream videos so smooth. And you can also record the streamed video on iPhone.

This is the most tiny and easiest way of broadcasting system in the world.

Cyntact is an application which enables contact list of iPhone's AddressBook to display photo icon.

I don't register photos of my friends in AddressBook, so you can see only icons on the left side of the list in the sample image.

I guess this function will be applied officialy by Apple in future release of iPhone OS.

New version of Modem application for iPhone "PdaNet" supports USB connection (Windows only).

WiFi Router Mode and USB Mode are listed in its new settings.

This version is more stable and reliable than previous version.