AI am making a small 8" fruit cake for a gentleman turning 80. No particular hobbies so a bit stumped for ideas re decoration. The decoration will be fondant over marzipan. Any thoughts welcome. Many thanks

Here are a few men's cakes I have made that might spark an idea for you to follow through on.  I know the last one is much bigger than you need along w/being for a lady but thought the general idea might help.

google images "80th birthday cakes for men" lots of pictures there.

I think you should be thinking simple but classy. Maybe a stripe or checkerboard pattern. I love the look of something like this.

I also love the look of pairing it with some chocolate. 

And it doesn't have to be that big, I know you're doing a small cake, it was just the colours and pattern that caught my eye. It's something I'd make for my dad. 

ALove the striped one - will give this some thought. Many Thanks Nadiaa and everyone for your suggestions - gets the old gray matter going thank goodness

How about a cake that looks like a Victrola?

When my Dad turned 80 I did a knight attacking a dragon (my avatar) on a pile of gold with a scroll saying, 'From the Mists of Time, Sir Charles, A legend in the Making'. ( I needed to allude to how awsome he is but also how ancient he is getting, whilst still allowing him to get even older and even better). I put an 80 on the knight's shield. 

ACazza, I always wondered what your avatar was!! :)