As one who managed to end a three-packets-a-day addiction to cigarettes on reaching the age of 40, I am naturally sympathetic to anyone engaging in a fight with nicotine. That said, playwright Simon Gray rather tries one's patience in a new book chronicling his efforts to give up through the evident weakness of his resolve. As readers of the previous two volumes of his Smoking Diaries will know, his has been a long and fruitful love affair with tobacco. His infatuation with the weed has been deeper then ever in recent years since his doctors ordered him to cease indulging, to any degree, in another pleasure of his life, alcohol. From Page 1 of The Last Cigarette (Granta, £14.99), the reader is in no doubt that it won't deliver what it says on the packet. Last cigarette? As far as Gray is concerned, this appears still to be in the future.

The book, I need hardly say, is a joy from beginning to end. His discursive, stream-of-consciousness style is exactly to my taste. So, too, is his knack for witty description as he leads us on a jolly ramble through his increasingly leisured life. I read somewhere that this is to be his last book of this sort. I hope this is not the case, for publication of each new volume is something I look forward to hugely - as do a number of my more curmudgeonly pals.

This time, because the poor chap is ill with cancer, there is less than usual about Sir Harold Pinter, who has developed as the series has progressed into one of the great comic characters of modern times. Gray remains in close contact by telephone, however, from whichever holiday spot around the world he and his wife Victoria (dedicatee of this volume) happen to be lazing in. He also provides a character summary of Pinter which seems, to this reader at least, to go rather further than might be considered polite or politic in describing his friend's strange behaviour.

He writes: "When he becomes angry the eyes go milky, the voice a brutal weapon that is virtually without content. What I mean by this is that he speaks violently, really violently. His voice is like a fist driving into you, but he uses almost no words, three or four at most there follow a number of expletives . . . It is the drink, of course, but it isn't only the drink, of course. The primitive, I really wanted to write the primeval, savagery of Harold's rages comes from somewhere or something drink may have opened the way to, but isn't itself created by drink. It is a chaos of self."

Excellent observer that he is most of the time, Gray can sometimes reveal surprising lacunae in his knowledge and understanding of what is around him. I was puzzled, for instance, by one of his observations about the Greek port of Piraeus, through which he passes on the way to Spetses. He writes: "When we got there, it was . . . foul as I remember it from five years ago, and all the years before that, the afternoon sun beating down, no bars and cafés, and the only shade from a long strip of tarpaulin some distance from the quay." Anyone who has ever been to the port will spot the error straightaway. "No bars and cafés"! There are at least five busy bars, in most of which I have whiled away an hour or two while waiting for morning ferries to the island. The biggest has a nice line in cockroaches, so be careful where you put your feet.

Gray also has another bash at that easy target, Milton Keynes - bizarrely at its theatre. This resumes where he left off in The Year of the Jouncer, describing the opening of his play The Holy Terror there. He wrote: "Milton Keynes with its wide desolate boulevards, its noisy ghastly mall, a town designed for a future that it's somehow missed, so it's both aggressively modern and hopelessly out of date. The theatre, naturally, is vast and ugly, inside and out. I forgot to ask how many seats but I'd guess, as a minimum, twelve hundred, it probably does lots of pop shows, that sort of thing . . ."

Actually, the sort of thing that Milton Keynes Theatre does is a mixture of first-class theatre, musicals and opera. It does no pop shows at all. Highlights of its recent programme, all of which I have attended, included Verdi's Falstaff with Bryn Terfel, Chekhov's Uncle Vanya with a brilliant Neil Pearson as Dr Astrov and Peter Shaffer's Equus, with Gray's pal Simon Callow in the role of the shrink, Dysart.