Danny Baker divides public opinion violently. He is either one of the most intelligent, idiosyncratic and funny broadcasters around, or he's just Chris Evans's talentless Cockney loudmouth mate. I've been in the former camp since he presented the Radio 5 breakfast show Morning Edition a decade ago. He became a standard-bearer for Matthew Bannister's all-new Radio 1 in 1993, when the then director general of the BBC, John Birt, spoke warmly of his "invigorating torrents of thought".

Although couched in Birtspeak, this is true enough - Baker throws off ideas like a firework throws off sparks. Unfortunately, clay pigeon shooting with CDs (just one of the ideas he had at Radio 1) was not to everyone's taste. So eventually he returned to GLR - where he had begun his radio career. Then it was Virgin, before returning to Saturday mornings on BBC London, as GLR had become. Now, joined by his long-suffering sidekick Allis Moss, he is the weekday breakfast host, billing the move as "Capital's worst nightmare", and intending to chase the rival station "right up a tree".

It's an interesting experiment. Breakfast shows are heavily formatted, and Baker doesn't like sticking to formats. He got away with murder at Radio 5 and at BBC London on Saturdays. At breakfast, however, travel bulletins occur every 15 minutes, with news every half-hour. Also, this gig is all speech, and although Baker's shows have always been speech-heavy, music has been a vital ingredient.

However, on the evidence of day one, a healthy compromise has been reached. Baker gets to play song introductions and bemoan the fact that he isn't allowed the whole record. He is also allowed to set wilfully obscure competitions about vertically challenged actors and Worthington E, the prize being a measly pound coin. (The inaugural quid was won by this writer, incidentally.)

In addition, the bosses get to inject financial, travel and entertainment bulletins into the show as formatted, as long as Baker gets to harangue the poor hacks involved and their guests. As well as asking the lead singer of the Bluetones what right the group had to release a greatest hits collection, he accused the political correspondent of peddling a non-story: "Saying that Tony Blair is coming back to face angry backbenchers is like saying that a milkman has to get up early in the morning. It's his job."

The financial news (Baker advised listeners to keep a close eye on Capital's share price) came down the line from Swindon, prompting him to imagine the correspondent broadcasting to London from his Wiltshire home, "lying on his back wearing one of those silk smoking jackets and a pork-pie hat". One story involved Marconi ("I believe he's spinning in his grave right now," he joked), and he asked the specialist how a company that was "£3.5bn in the hole" could carry on trading. Although the question had a frivolous edge, it succeeded in eliciting an excellent, jargon-free explanation of the company's malaise.

The highlight of day one, however, was the appearance of Sir Clement Freud, booked ostensibly to do a six-minute review of the papers, but who stayed for half an hour, rambling on about horse racing and his liberal schooling, while offering delightfully irrelevant alternative travel information. "There's not much traffic in Walberswick, Suffolk," was Freud's final report.

There's some fine-tuning to be done, but this is already a breakfast show like no other - a hybrid of Wogan's whimsy, the Today programme, the US shock-jock Howard Stern and some very clued-up pub chatter. Baker saw it in simpler terms: "I thought we were having a private conversation, but there seems to be a radio show going on." I don't think there's a better description of good speech broadcasting.

BBC London is available on 94.9 MHz VHF and on the internet at www.bbc.co.uk/london. Danny Baker's breakfast show is on weekdays between 6am and 9am