Royal Mail code 128 barcode creator
The UK Royal Mail use barcodes based on the code 128 format. "Based" is the catch, as they use a custom format which took me a few headscratches to work out and then a few more to get the resulting barcode validated by them.
Here's a small configurable php script which creates the barcode image using GD.
Please do not hotlink to any files - it will not work.