I would definately keep the book. I actually bought an original copy just last year to add to my collection as i only had the 'Dean' edition, which has the altered names. I think it should be looked on in context. We might find the names offensive today, but they were looked on as acceptable at the time the book was written, as Anita says.
The thing I find interesting is that some people nowadays would find the whole
book offensive, even with the changed names. The book is not published at all in its original form nowadays, or with golliwogs as its central characters ( I believe in even later editions they are now pixies or elves).
My personal favourite edition of this book is the 'Dean' edition I read as a child. The names are changed in this to Wiggie, Waggie and Wollie. I love the illustrations in this edition by Rene Cloke.
The worst appearence of the three golliwogs, I think, is in the Enid blyton play 'Noddy in Toyland' in which they sing a song about themselves all looking the same. It was intended as funny, but nowadays seems more insulting than amusing.
So dont throw the book away, but keep it as a reminder of less tolerent times - and buy the 'Dean' edition if you want to enjoy reading the stories you remember!