Jailbreak iphone 3G 4.2.1

The volume up and volume down buttons have died on my iphone 3G 4.2.1
I have searched the appstore and can not find a phone volume control.  I can find apps that control almost any other volume function but not a volume control for the phone.

OK so it seems things have gotten easier in the jail breaking arean
A fellow by the name of Comex has a web site called "jailbreakme.com".
Apparantly one just visits this web site and he presto.
BACKUP:-
First I copy all the photos onto my netbook.
Then I let itunes do a sync
VISIT  "jailbreakme.com"
Blast.  I have a 3G and it is not supported by the website.
I understand it will work on iPhone 3G on iOS 4.0.1
I appear to have 4.2.1. Downgrading seems to be hard.
REDSNOW
There are a number of jail breaking programs.
Chose redsnow for no particular reason.
This is a useful web page
https://sites.google.com/a/iphone-dev.com/files/home/
Downloaded   redsn0w_win_0.9.6rc16 from
 https://sites.google.com/a/iphone-dev.com/files/home/redsn0w_win_0.9.6rc16.zip?attredirects=0&d=1
Downloaded the os for the ipone 3G from Apple
http://appldnld.apple.com/iPhone4/061-9853.20101122.Vfgt5/iPhone1,2_4.2.1_8C148_Restore.ipsw
This turned up with a .zip extension so I just renamed it as .ipsw
ENTERED DFU MODE

1. Plug iphone onto pc.
2. Hold power button down until it ask you to power off.
3. Power it off.
4. Press and hold Power Button.
5. Press and hold round button
6. Watch the clock and time 10 seconds.
7. Release power button but keep holding round button for a further 15 seconds.
8. This should cause it to boot to DFU mode.  note the screen is blank in DFU mode.

RAN REDSN0W
Browsed for the ios 4.2.1  .ipsw file which it hapily injested.

On the win 7 netbook it eventually displayed "waiting for reset" and hung.  Tried it a few times including running as administrator.
Gave up.
Used itunes on the Win7 netbook to restore it.

Then tried again on Dan's XP laptop.  Initially would not work.  Then I downloaded itunes and it worked.  Seems Redsn0w required itunes to be loaded on the computer but not running.  I guess it needs the drivers.

Now we have a jailbroken iphone 3G but all is not perfect.
There are black lines that flash on the screen when one changes screens.  As if the processor were running slow.  Also I can not find SBSettings on Cydia.  I can find all sorts of skins or themes for it but not the actual program.

I can not find an APP for adjusting incall volume.
This blog has a method of adjusting the incall volume by editing some config file but it needs SBSettings so for the moment I am giving up.
http://meethapaan.blogspot.com/2010/05/iphone-volume-button-broken-software.html

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5-OCT-2011 UPDATE
The jailbroken phone is slow, the battery life is poor, the browser does not work and I do not seem to be able to send texts messages.  Now it could be because of the messing about jailbreaking on different computers but right now, I am going to restore it to its former Apple glory albeit with no in call volume control for the phone.  which I don't have anyway!.

Plugged it onto laptop. I tunes started up.
It asked if I wanted to backup and I said "no thanks"
itunes states "iTunes is restoring the software on this iPhone"
The screen has flickered a few times and has a white apple and a progress bar.
now it all works again.