Is there any web app that can generate barcodes for me?
If you need 2D QR barcodes, you can use Google Chart API:
The barcode site at mribti.com has many options avalable.
It's also used on the Barcode Label Printer - Free Online Barcode Generator tool on barcodesinc.com.
You can find a pure ASP barcode generator source here: http://www.planetsourcecode.com/vb/scripts/ShowCode.asp?txtCodeId=8817&lngWId=4
Probably the best online generator for 2D-barcodes (of any type, not just QR) is http://keremerkan.net/qr-code-and-2d-code-generator/
My new site blinked.in might have what you're looking for. It's entirely devoted to the subject of barcodes (UPCs and EANs), amongst the sites features:
- Renderering as PNG / SVG
- Batch validation
- A constantly expanding, 15M entry product database
- A public API
- A Windows Phone 8 App
- A Windows 8 App
We're still very early in our development - there's a dedicated alpha status page that shows how we're doing!