I frequently read that in my META tags I should lay it out like:
place, here, now - (with the spaces between the commas) but I sometimes read it should be
place,here,now - (without the spaces...)
Does this make any difference to the way that search engines will index the page?
No, it doesn't make a difference. You can put in the spaces or leave them out and search engines will view your meta tags as the same.
The spaces only take up space and dilute the relevancy of the words further down the list, get rid of them. Alternatively try just using spaces to form a long phrase then searches will hit phrases instead of individual words which increases relevance.
Simon Conroy, Acorn Internet Search Engine Placement