I am having heart palpitations, my hands are shaking and my mouth is dry. The things I do for research.

I've had a caffeine overdose because I have been out and about in London on a wi-fi safari.

Wi-fi hotspots are public places, usually cafes, where those equipped with wi-fi facilities on their laptop or PDA can surf the internet and send and receive email wirelessly at broadband speeds.

Enormous things are being claimed for wi-fi, yet for it to stand any chance of becoming more than a niche for business users it needs to be cheap and simple to use.

So armed with my laptop I headed for Farringdon near the Guardian Unlimited HQ in central London to find out how easy it is to turn up at a hotspot, switch on a PC and surf.

First port of call was Starbucks on Cowcross Street. The American coffee chain has a deal with T-Mobile and offers wi-fi access in five sites across the capital. I ordered a coffee and Panini and explained I fancied some wireless high-speed internet access on the side.

After a moment or two's thought my server thrust a leaflet in my hand and told me to follow the instructions. I headed off to the basement seating area, got out my laptop, fired up my browser and waited.

A few seconds later the home page appeared and I was asked to fill in my details. After entering my password and credit card details, I plumped for £14 for 120 minutes' access across 28 days (it's £5.50 for a one-off hour long session).

Overall it was a pretty pleasant way to spend half an hour. Web access was quick and easy and the seating area is nice enough. There's even a plug socket if you are low on power. A good start.

Just down the road, Costa Coffee is offering wi-fi via a deal with BT Openzone. Again the staff didn't seem especially interested in answering my questions; rather they shoved a leaflet at me and left me to my own devices.

On opening the web browser the BT page appeared and my troubles began. Login proved to be a painful and time-consuming experience. It was around seven or eight minutes before my home page finally appeared.

Had I popped in for a quick slurp of my coffee and to check my email, or even worse been surfing via my Palm rather than my laptop, I'd have given up. Pricing isn't great either. I paid £6 for an hour's access over a 24-hour period.

Benugo seemed to be offering a deal too good to miss. At two of its classy sandwich stores (the one I visited was in St John's St, Clerkenwell, and a second in Soho's Berwick St) you can surf wirelessly for half an hour freely as long as you've spent more than £2 on food and drinks.

The staff knew exactly what I wanted. They gave me a piece of paper with a six-character password on it and told me to open up my web browser. Sure enough I landed straight on Benugo's home page, and after I'd put in the password I was away cruising the net. No need for credit card details, address or user names.

Surely, if wi-fi is to establish itself as mainstream technology, the quick, free and easy Benugo route has to be the one to go for. The staff told me that at least 20 geeks access the internet via their WLAN each day, which might not sound much but in terms of hotspots that's quite an impressive figure.

I finally headed to Leman St on the edge of the City of London to check out the Old Monk - one of the capital's first wi-fi pubs. An organisation called the Cloud last week took more than 200 of the UK's boozers online via wireless networks, and although it intends to charge for access for the time being it is free.

Initial impressions weren't good. I ordered a pint (purely in the interests of research) and asked the barman about getting online. He shrugged his shoulders. I looked around the pub, no leaflets or signs. Maybe I had come to the wrong place?

I switched on my laptop and checked the wireless monitor - no signal. Just as I was about to give up the barman pointed me in the direction of a games machine, where he said there were instructions for accessing something wireless.

I read and followed the instructions, but still no signal. Giving the Cloud one last chance I rang their helpline from my mobile only to be told that the number doesn't exist.

Finally I got through to the company office and left a message for the operations manager. Are they being a little economical with the truth about how many pubs are now online?

After about 20 minutes he returned my call to explain there was a router problem at the Old Monk that would be fixed later that day. He added that it sounded like my mobile phone network wouldn't access premium rate numbers like the Cloud's helpline.

To be honest, by then I was more interested in lining up my third beer than checking my email anyway.