There are several small islands just off the coast of La Digue:
There are several ferries a day the run between the port of Praslin, and La Digue costs round trip are aproximatley 40 euro as of 2011. There are also several locals of Praslin that offer boats for hire, however this option is very expensive. Expect to pay aproximatly 600 euro and upwards. If you go this route you will have the chance to stop at some of the other less accessible islands in the area as well.
Due to it's small size, La Digue has little need for the transportation infrastructure seen in Mahe or even Pralin. There are only a handful of taxis for hire on the island, and no car rental agencies. As a result of the low supply, prices for taxi are high - approximately 90 Euro for a half day or 30 Euro for a trip to the beach. If you are staying at one of the resorts on the island, your hotel will likely arrange for ferry pick up, but check before hand to ensure you are not stranded. For those arriving by ferry for a day trip, you will see many companies offering bikes for rent. This is really the only way to travel around the island, and quite affordable at about 8 euros for a whole day, just make sure you test your bike before you take it. If you aren't going very far, there are also ox carts (a buggy pulled by an ox) that you can catch a ride on.
There are several gift shops on the island, most of them right by the port. They offer the usual gifts of Seychelles. One notable purchase is fresh vanilla beans grown right on the island. 9 beans cost around 5 euros, a fantastic price, and cheaper then the beans on Praslin. Also if you visit the visitors center, they have free full color posters (1 per person) available.
There are several Creole take-away/take-out restaurants available in town offering curry, fish, pork, and rice dishes. For non-adventurous diners there is a very pricey resort style restaurant offering Western style meals, as well as seafood. There is also a small gelato shop (ice cream) just south of town on the main road.
As the island is very small, very few people stay over night. However if you choose to, or if you miss the last ferry at 5:00 pm, there are expensive hotels, guest houses, antique hotels in town ($150 - $600 plus a night). It's a much better option to just plan on a day trip to the island, which is plenty of time to see all of the sites unless you have a stay overnight event, such as a wedding, booked.
Here is the website for the island: http://www.ladigue.sc/