That's the correct cable. Don't worry that it doesn't specifically state the a670, it's compatible. It comes with the Futuredial software, but you don't have to use it. I use QPST to transfer files. You can also use Bitpim or Gagin.
When you're connected, you'll see a /brew folder. /brew/ringer is where ringtones go, and /brew/shared is where wallpapers go. If those directories don't exist, just create them.
Ringers need to be less than 30k, and in .mid (for polyphonic) or .pmd (voice) formats. You can get use CMX Studio to convert .wav to .pmd, but .pmd ringers need to be less than 16 seconds to stay under 30k.
Wallpapers are 128x128 px (unless you want them to fill the screen that is normally hidden behind the banners, for startup and shutdown, then it's a little bigger, I'm not sure what the exact size is) and need to be bitmap format with an indexed color palette, otherwise you get little white dots on the image when you see it on your phone.
Also, if you want free WAP (you'll still have to pay for airtime) go to Menu-5-0, and it will ask you for a user lock code. Your user lock code is the last 4 digits of your cell number. Then go to Gateway>Address>Address 1 and change it to 188.8.131.52. Then go back to Gateway>Port>Port 1 and change it to 9201.
So I have an a670 as well, I was looking at your service manual layout. Is there a link/page/manual i can learn what each of these are? ie DTMF on _____* etc. I dont plan on trying anything with it until i get an understanding of the codes that govern each function. Thanks.
Save the message to your "Saved Box" and then open it from the Saved Box. Hit View, Option, and then go down to 3-Save Text, and scroll to the right until it says "Save Picture." Save it, and you should be able to set it as your wallpaper through Main menu>7>2>2>3>3 (My Image)
There will be a white border around the image though, there's not much you can do about that unless you use a USB cable.
No idea. I'm not sure if it does that when it is sent to you, or when you save it. It is kind of annoying, though. If you had the cable you could take it off the phone to your PC, crop it how you like, and send it back.