since the launch of N95 ive been using this cool feature built into the phone.
THE BARCODE READER.
no this is not the 1D barcodes you find you in grocery goods.
2D barcodes contain Web addresses, vCard (name and number), messages, etc.

so next time you see images like the one above, point your phone at it
this FREE READER is now preinstalled in most highend nokia's like N82, N93, N93i, N95, N95 8GB, E66, E71, E90 or 6220 Classic ETC.
if you have a Nokia N78, N85, N86, 6210 Navigator, N96 and 6220 ETC. which may not have this reader preintalled you man install it by downloading it at
nokia site
now ive also tested other FREE readers that can work with most camera phones out there (regardless of brand and OS)
I-nigma reader, by 3GVision
Install via mobile browser:
http://www.i-nigma.mobi

or download to a computer and transfer it to your mobile device from
i-nigma - the fast track to mobile internet
NeoReader, by NeoMedia Technologies / Gavitec AG - mobile digit
Install via mobile browser:
ID handset
UpCode reader, by UPC
Install via mobile browser:
UpCode - Ignite Your Imagination - UpCode Ltd.

or download to a computer and transfer it to your mobile device from
UpCode - Ignite Your Imagination - Download for free
Semacode reader, by Semacode
Install via mobile browser:
Semacode : Weblog : Download

or download to a computer and transfer it to your mobile device from
semacode.org/software/
QuickMark reader
Download to a computer and transfer ir to your mobile device from
QuickMark Mobile Barcode - Web Site QuickMark
Kaywa QR reader
The Kaywa Reader
Zebra Scan
ZebraScan - Free barcode scanner for mobiles
each have pros and cons. while the nokia barcode reader does the job pretty darn well as it is...having alternatives never hurt.
Upcode offers 1D reading aside from the 2D allowing you to read barcodes on cellphone boxes and grocery goods. however its 2D reading i find to be slower and less sensitive that the nokia. this most evident if you are trying to read a very complex 2D barcode with a lot of information.
I-nigma is my fav in reading 2D barcodes coz its the most sensitive and fastest however loading the app takes the longest. going to its site via the phone
http://www.i-nigma.mobi automatically detects what phone you have and what version to install...simply cool!
to create your own 2D code try this
Nokia Mobile Codes - Create, Share and Scan QR and Datamatrix barcodes
http://qrcode.kaywa.com/
also found a nifty firefox plugin
https://addons.mozilla.org/en-US/firefox/addon/2780