Over a year after quietly introducing the feature in the USA, Google has added the ability to send money through Gmail in the United Kingdom. While Google likes to emphasize the fact that you're sending the money through Gmail, it's really done via Google Wallet. The main benefit is that you can embed the send/receive request within an email message and Google will do the heavy lifting for you in terms of enticing the recipient to sign up for a Wallet account, if necessary.
Sending is fairly easy if you already have a Wallet account. Attach the "money" just like you would a file.
It is a nice integration of Google's services, something we don't always get. For those in the UK, it is at least a nice sign that Google is working at bringing their full range of products overseas, something they aren't always so attentive to.
The feature should be live, so go and try it out for yourself. American readers should have this already, but it's fairly easy to overlook. Sending money through Gmail may not be the most critical feature, but it definitely can be convenient. Also, for now, this is for the desktop client only. You'll need to stick to the Wallet app on Android.
Source: Google Commerce