Huge thank you to everyone for all of your great suggestions.
BlueJays suggestion of the DP-1 sounds good but then dubbleyew's and Jude098's diversion techniques sound cheaper and as effective...(?)
I like pudoc's idea of a GPS for after I have my PPL but could I not just use the GPS on a mobile phone to confirm where I am on the chart? I appreciate that it would probably be better (in the sense of cutting down on workload) if the GPS and chart was combined though. I already have a cheapie A5 kneeboard (£2.50 from Staples) which has done the trick so far along with the 1:500000 chart & pens. A carbon monoxide detector is a good idea as the flight school's planes don't have any detectors in them already. Although a carbon monoxide detector isn't the most exciting of gifts I do like the idea of not slipping into a coma at 3,000 feet!
John's helicopter flight sounds fun but as I commute up to London from Brighton Monday-Friday I do get quite sick of the place tbh. I also like Benjybh's idea of a gliding lesson. Even though my main passion is powered flight I am drawn to gliding...possibly/probably after getting my PPL I'll give it a go.
As I'm based in Shoreham Blues & Two's and Foxmoth's suggestion of an aerobatic flight sounds excellent. I was considering aerobatic training after getting my PPL.
As I'm a fair way through the PPL course I already have a bag and headset.
A great suggestion by Riverrock about a mag subscription as is all of Taybird's ideas.
And I'm definitely going to go for the epaulettes and wig, Jonzarno!
Once again, thanks fellas. Keep them coming if you think of anything else.