There are many internet cafes in Maseru, and although they are reasonably priced (about LSL0.20-0.50 per minute), they are at best sluggish.
The mobile network is adequate in cities but deplorable in the countryside. Vodafone is the only British mobile phone network that has a roaming agreement. Lesotho has two mobile operators: Vodacom and Econet Telecom Lesoth. Outside of towns, Vodacom offers the best coverage, but it is also the most (over)subscribed and therefore the least dependable. In Maseru, you can get a Vodacom or Ezicel Buddie pay as you go sim card for less than LSL50, which is useful if you plan on staying for a long. In Maseru, cell phones may be rented. Lesotho uses GSM900. Both networks are currently very excellent, with 4G capabilities.
If you have a South African Vodacom Sim Card, you can only use it on the Vodacom network in Lesotho. Make sure that roaming is turned on.