Get around by Green TaxiCabs. Some people will tell you to avoid the taxi's with the drivers chewing Khat. Khat is not a narcotic, but a stimulant more mild than Meth, or Coke. It gives the local Djiboutians and Somalis something called Merran the Somali word for 'energy'.
Taxis range from 500fr to any amount, depending on how far you go.
Camp Lemonier to Downtown 1,500FRDowntown to Kempinski 2,000FRBase to Kempinski 2,500FR
Again, negotiate and you may get a lower price, but there are better things to do than to argue over 500fr 3 American dollars.