A couple of weeks ago I wrote about my frustrating efforts to use various new mobile money applications on my phone. I promised then to have another go, to give up cash and try to pay by phone alone. So, how did it go? Not very well, I'm afraid.
I started by loading up my phone with a variety of apps which - supposedly - would help me get by without cash or even cards. My main weapons were to be O2 Wallet and Barclays Pingit, two new services which allow you to send and receive money from your phone. But I also installed the Paypal app, and a range of others that allow you to buy a coffee or pay for a taxi from your phone.
Within minutes of starting, I ran into trouble. It was my turn to buy the office tea and coffee round, and the coffee outlet only took cash. No problem - I would get my colleague Anthony to pay and refund him via one of my mobile money pay-by-text services.
With Barclays Pingit playing up (I never got it to work, even after deleting the app and going through the lengthy verification system again) I turned to my O2 wallet. Just two or three passwords later, I had texted a £2.80 money message to Anthony.
Then the fun began.
He spent days - quite literally - trying to make sure this and a couple of other payments from me made their way from his phone into his bank account. Much of that time was spent in increasingly intemperate phone conversations with O2. At one point the company told him their "triage unit" was on the case. Anthony's verdict? "No need for triage - it's terminal!"
I quickly realised that although I wanted to rely solely on my phone, this approach wasn't going to work. I would need to use credit and debit cards as well, plus my Oyster touch-and-go card for travel around London.
By paying for meals via my debit card - which meant I had to spend more than £5 - I did manage to get by without cash for a couple of days.
Then I took a trip to Oxford and had my first failure.
Getting on a bus to the city centre without a travelcard, I found myself obliged to dip into my pocket for some coins to pay the fare. And my bus trip proved a timely example of how useful mobile money could be if it were more widely adopted. On a busy route, every time we stopped dozens of school children and students queued to pay by cash, making our progress very slow.
While neither of my mobile money services proved at all useful over the week, there were two things - taxis and coffee - that proved easy to pay for by phone. The taxi app market is now fiercely competitive and I found Hailo, a service that lets you order a London cab, pretty efficient at delivering a driver to me within five minutes.
I also tried Ubicabs to order minicabs, and this again worked fine - although my driver ended up asking me to navigate to my destination. These services make it very easy to move around without cash or credit cards - if only in the London area - but they have one major downside. You end up racking up big bills without even thinking about it.
The same applies with the Starbucks app, which allows you to load money onto a virtual payment card on your phone, then swipe your phone against a reader to pay for coffee or a sandwich. Because this was the only easy way I found to buy food from my phone, I ended up spending far too much on cappuccinos.
When I ended my experiment, I breathed a sigh of relief - as did my colleague Anthony, who is still trying to extract from his phone the money I owe him. Trying to live off mobile money, which is supposed to make life easier, has been a stressful experience. The inevitable concerns about security are making most of these new services so complicated to use that you have to be slightly deranged even to bother.
That is not to say the whole idea is doomed to failure. We will see further innovation over the coming weeks as payments firms unveil plans to allow visitors to the London Olympics to pay with their phones.
But here's my advice to the companies pushing these services - your "triage units" are in for a busy time.