Larry King, as ever, was to the point: "One fifth of internet dot.coms have gone bust, investors are $3 trillion poorer and 40,000 more people are unemployed as a result of the dot.com crash. To borrow a line from the film, isn't it time to show me the money?"

The talk show host was acting as a compere at Accenture's global communications forum in Miami Beach, Florida.

The audience of executives from more than 160 of the world's biggest telecoms, media and technology companies, was looking a little red-faced - and not entirely because they had been spending too much time on the loungers by the pool. A year ago these executives from global organisations such as News Corp, Orange, EMI and Nortel Networks were detailing how they were going to make billions from the coming technology revolution.

Twelve months on, all the talk is about tougher times ahead. As Ameet Shah, a partner at Accenture, says: "We've woken up and realised that the world wasn't quite what we dreamt it was."

His colleague, Tom Pike, head of strategy, admits the future is pretty uncertain too: "The fundamental case for the way technology is transforming business remains unchanged, and we're bullish on a three- to five-year basis but it's impossible to predict how the next 12 months is going to pan out."

The stakes are high. Chuck Phillips - managing director at Morgan Stanley - said that 70% of all money put into technology companies over the last 25 years was invested in 1999 and 2000.

During that time almost 6m miles of fibre was laid underground, hundreds of billions of dollars was spent on wireless licences and price to earnings ratios for stocks reached 200-year highs.

The vast majority of companies now have to show they can turn customers into hard cash, Mr Phillips said. "It's been brutal, and we cannot count on raw new internet users to generate growth," he said. "Users and usage may still be growing but the rate of that growth is slowing, and we need to find new uses for the net."

Several new technologies have disappointed or been delayed. Duane Ackerman, chief executive of cable company Bell South, believes the roll-out of broadband and higher speed internet access will bring revenue opportunities but says companies must think carefully about how they exploit them and spend cautiously.

Wireless operators, spending £200bn on third generation licences and set-up costs in Europe, have the biggest mountain to climb, according to Jean François Cecillon, former head of Sega Europe.

"Mobile content has to get better," he said. "Weather reports and stock updates are all very nice but that doesn't hook me. There is no way that is going to pay back £200bn."

Ericsson director Ulf Bromster believes operators and manufacturers have learned their lesson from the under-whelming response to Wap, the wireless internet platform that was introduced to Europeans last year. "There's not going to be any big bang with 3G and it will take time to come through, but we'll see steady growth in wireless internet over the next few years."

Ameet Shah believes only a few of the wireless companies will survive in their present form, with most either being acquired or going bust.

Morgan Stanley's Mr Phillips believes supply chain management and B2B exchanges will continue to show good growth despite the downturn.

However, he is not expecting the investment bank to cash in in quite the same way it has over the last two years.

"We all had a great time, got our houses remodeled and bought new cars, but those days are over now," he said.