What to get as a gift for a now-retired ATCO?

A colleague at work and personal friend's dad is a recently retired ATCO
officer whom has worked at EGLL / LHR for about 30 years.

The chap has done much for me and for many others, so I wanted to send a
thank-you gift that tied in to aviation and perhaps ATC operation.

I know what kind of gifts that pilots, CFIs, etc. likes... but I'm not
sure what to get for a veteran ATCO that will really mean something.

He's also very bright, and good with technology; always tinkering with
all sorts of stuff like GPS receivers, nicer tools like Adobe Photoshop,
etc.

I don't want to say much more about this chap since he hangs out online
in other aviation forums, and I don't wish to 'let the cat out of the
bag' early.

Nor do I want to ask in forums dedicated to ATC since it's a very small
community. But he's a very fine bloke, both personally and
professionally, and a credit to his family and former colleagues.

Any suggestions? Are there particular gifts that are traditionally given
to retiring ATCOs? Any ideas would be most welcome.

-Dan