Fuel funnel
Although you can pick up dodgy fuel from anywhere, jerry cans from retail shacks on the side of the road have all the risks of cleaning your teeth in the toilet bowl. If you don't have sufficient fuel on board, I'd recommend getting a funnel called "Mr Funnel". Stay with me on this - I'm not taking the wotsit. It's an American funnel, which has a very fine filter. As well as general desert sand, it filters out water.

Do a search for "Mr Funnel" on the internet. You'll be taking a funnel with you anyway, so it might as well be a filtered funnel, and one which filters out water.

Take a bike
If you're travelling by road in your vehicle, try to strap a bike to it somewhere.

In towns, a bike gives you complete freedom. Wandering through markets, along streets and into parks. Far better than walking, infinitely more flexible than the bus, and ... it gets you amongst the local population better than anything else.

Business cards

As you travel, you'll end up scribbling your contact details on all sorts of newspapers corners and cigarette packets for fellow travellers and people generally interested in your journey.

Getting sick of people being unable to read my handwriting, a simple "business card" was knocked up on the computer. Something I should have done at the outset of the journey.

Including a picture of your vehicle or yourself will help prevent the "Who the hell was this?" comment a week later. Some cards can include your home address, while others can have only basic contact info.

Ultrasonic mosquito repellent devices
Forget them: they don't work.

Don't waste your money thinking this option will save carrying mosquito mats for the usual electrical plug-in mosquito repellent machines (indoors) and the coils (outdoors).