Until Installer gets back on 2.0, I'd thot I'd dig up my favorite SMS tone from my personal installer repo, FightClub.
This SMS tone is very very loud, and those of you who are ex-Nokia users might find it pretty familiar
Simply put, I can hear this tone from one office over at work, and I never miss an SMS now.
To install, download and unzip the attachment.
Browse to the folder below and rename the stock sms-recieved6.caf file to something simple, like adding a .bak to it in the picture below. Then just upload the replacement from the zip file.
Next browse to the directory below, and rename
Now just goto Settings > Sounds > SMS Tones on your iphone and select Electronic (I hate that sound), and you'll hear the new Louder SMS Tone!
Finally, I've got my loud SMS tone on my 2.0 iphone!
Note - Its recommended you Restart/Respring yoru iphone after installing this new SMS Tone. I've recently noticed that you may not hear the tone after immediately replacing the old one until you restart/respring. An easy way to test this out is to goto your sound preferences and select the Electronic Tone. If you don't hear anything, restart/respring and you'll be able to hear the new tone correctly.
I'll be hosting this for an automatic install on my Repo once Installer 4.0 goes live.