http://www.bikerevolution.org/

to register their bikes/get the barcode tag things?

£8 a bike for the 10 bikes I currently have in the house feels a bit heavy for the bar code sticker and reader app but wondering about recording their details on the site 'just in case' (and at least I could point to it for insurance purposes if any do go)?

I have been using http://www.BikeRegistry.com for several years, no probs and their sticker kits are only USD 1 per bike.

Instead of relying on some fancy-smancy bar code the BikeRegisry system utilizes the already in place serial number and bike details to catalog it in its database.
BikeRegistry.com