There are daily flights from Glasgow and from Inverness via Stornoway with Logan Air (operated by British Airways). Highland Airways also has direct flights from Inverness to Benbecula). You can also fly to Barra, south of Eriskay and land on the beach for an added thrill. There are bus and ferry connections to Eriskay and a causeway over to South Uist.
Caledonian MacBrayne run several ferries from the mainland to the Uist. You can travel from Oban to Lochbosidale or Uig in Skye to Lochmaddy. They also run small ferries from Eriskay to South Uist and Bernary to Harris. Hopefully soon we will have a new sailing from Malaig to Lochboisdale.
The islands from Eriskay to Bernary are all linked together with causeways. Some roads still remain single track with passing place for your convenience.