Updated January 2017
Since 2013 French troops have been battling AQIM and similar in the northern desert region.
Although there’ve been attacks as far south as Bamako, Mali southwest of Mopti is safe to cross.

Malian CFA XOF exchange rates

Price of fuel
Diesel from around 585 CFA/litre – more in remote towns. Petrol is 695 CFA.

More than you think.

Useful languages
French, Arabic

Needed by all except French. You can just turn up and get the “laissez passer” at some borders for 15.000 CFA (~€20) which gives you a week to get a proper visa in Bamako free of charge. You  need to fill in a form and have 2 photos for up to 3 months, single-entry. This has been the case for many years although you do hear of it backfiring occasionally, possibly merely due to border officials trying it on.
No consulate in UK – nearest are 487 ave. Moliere, Bruxelles or Consulat du Mali 64 rue Pelleport, 75020 Paris, 75020, Paris (visa took 30 mins in February, 2010) See this post from 2010. Download visa forms below. It can take up to 2-3 days from when they get it. Useful visa agency in NL  (up to half the price of Brit agencies)

The Mali consulate in Rabat (Morocco).
7, Rue Thami Lamdaouar
GPS N33 58.7′ W06 50.0′
a few doors down from the Mauritanian embassy
€60, 1 hour

There is also a Mali consulate in Nouakchott
Ave de Palais des Congres
N18°06.48′ W15°58.73′
Two photos and photo copy of passport, 6500UM. Visas issued in as little as an hour.
And a consulate in Tamanrasset, Algeria, next to the Niger consulate, High Street south end (look for the flag as on the top of this page). Here they issue a 5-day pass in a day or so, but that route to Mali visa Tessalit is closed.

From Mauritania – the way most people arrive overland these days – you can pick up a Mali visa in Rabat (see above) or Nouakchott while you wait for 6500 oogs for 1 month (8000 for double entry and 10,000 for 2 months double entry. Two photos required). Or if you’re feeling lucky simply turn up at the border from Ayoun el Atrous at Diandioume (the road south to Nioro), where a Mali visa costs 15000 CFA or 25 euros and is valid for a month, (the exact price and duration may vary).

Yellow Fever ticket may still be required.

Border formalities
Buy laissez-passer (local ‘carnet’) and insurance (both cover the whole CFA currency zone).
According to this site (December 2013) due to several incursions in that area there is a compulsory military escort (soldier in car with gun) from the Mauritanian border to Nioro du Sahel (€50)  and another escort from there to Bamako.
Furthermore a c
orrupt brigade chief at the customs office in Nioro tries to enforce a customs escort on transiting travellers (so-called T1 carnet), all the way through the country. Avoid this at all costs and insist you enter as a tourist, otherwise you have a guard in your car (€75-100) who keeps your passport and papers and chooses your Bamako hotel and drive out of the country.

Desert pistes: although Timbuktu was ‘liberated’ by the French in January 2013, even in the good years exploring the Sahara to the north was never Mali’s highlight and will doubtless remain closed for a while. This includes the 1000-mile trans-Saharan Tanezrouft piste, leading up to Reggane in Algeria. Venturing into Gao or beyond Araouane, north of Timbuktu to the desolate salt mines at Taoudenni is a bad idea.