Ok Lyte.
Unless you have your own house, or live in building with more than 30 units, you have to get either ADSL or Cable. Cable has better upload speeds than Yahoo BB. Yahoo ~can~ have better down speeds. Depends on your distance as always.
As for getting a phone. Id recommend DoCoMo (the springloaded D901iS is awesome, and will be my next phone), however you will need some special papers. When you get your 外国人登録証明書 (Gaikokujintourokushoumeisho) you should ask them for a special paper that will prove you applied for the card. Consider it a temp. DoCoMo will require this for getting a phone.
If you ever do get down to Osaka, just give me a PM. I am really busy with projects at work, but I am always free to hang out in the evening.
P.S. Other Japan gaffers who didnt know... I will be in Tokyo next week on business if anyone is up for drinks!
EDIT: More phone advice that I forgot. If you are going to be a heavy internet user on your phone, get Pakehoudai (all you can use internet on the phone). I know quite a few Japan Gaffers use it and love it. Finally... you cant sign up for Yahoo BB without the Gaijin card (the application proof doesnt cut it) and it takes a month for it to all get installed. So get married to the idea of no internet for now. Lastly, if you can, try to get signed up for Yahoo BB at Yodobashi Camera. They are offering a PSP or a Slim PS2 for 7000 yen if you buy it when you sign up for Yahoo BB! Who knows what kinda special deals Yodobashi Multimedia Akiba will offer when it opens in September. (I hear it is an exact copy of the building in Umeda)
Finally, pick up Continue Magazine this month. It is a great little super hardcore magazine that has a shopping tour of Akiba along with an akiba photoshoot/interview it Chiaki Kuriyama (GoGo Yubari).