Rob Brydon is one of a modern army of comics whose trademark is their ubiquity as much as it is their undoubted talent.

And although he seems to make more appearances year by year, arguably Brydon's best - and defining - work were his early performances for the BBC in 'Marion and Geoff' and 'Human Remains'. In 'Marion and Geoff', Brydon, a comparative unknown, portrayed the lonesome and tragic Keith Barret whose monologues from the driver's seat of his car were moving, funny and poignant. From that moment on, Rob Brydon has largely been cast as a tragi-comic version of himself, to the extent where it has become unclear where Rob ends and where Keith Barret, or Gavin and Stacey's Uncle Bryn, begins.

In the Michael Winterbottom-directed BBC comedy The Trip, both Brydon and Steve Coogan played fictionalised versions of themselves but, with much of the comedy improvised, Brydon's natural character shone through. Or at least the character we get to see on panel shows like QI or Would I Lie to You?, the latter hosted by Brydon.

In The Trip, and in the film A Cock & Bull Story - in which Brydon also co-stars with Coogan and which Winterbottom also directed - Brydon trades Al Pacino impressions with Coogan. They are brilliant and hilarious (if you like that kind of thing) but they're the same impressions he does as 'himself'. The same goes for his Ken Bruce or Ronnie Corbett impersonations - in whatever carnation, Brydon never seems far from a Corbett or a Pacino.

One suspects that it is all an act. That, in apparently showing so much of himself, Brydon succeeds in remaining intensely private and keeping The Real Rob from view. One of his most popular voices is 'small man in a box' - he might well be that man, from whom we hear nothing more than the occasional strangulated cry for help.

Until now, that is. Brydon's book, 'A Small Man in a Book' is due for publication in October 2011 and is 'a funny, heartfelt, honest, sometimes sad, but mainly funny' memoir of how Brydon 'very, very slowly became an overnight success'.

To accompany the book, Rob Brydon is taking Small Man in a Book on the road with a series of dates starting on Monday 24th October at Newcastle's Journal Tyne Theatre. A fortnight later, after visits to Manchester, Cardiff, Edinburgh and others, Rob Brydon finishes the tour at the Lyric Theatre on London's Shaftesbury Avenue on Monday 7th November.

Tickets for the 13 dates are available now, starting at £14 (£17 for London).