Random.org has (among other things) a free HTTP API, and a new JSON API is currently (june 2016) in beta (keys on request).
The HTTP interface (using GET requests) has an Integer Generator, a Sequence Generator and a String Generator.
The JSON interface call names show what's available there:
generateIntegers, generateDecimalFractions, generateGaussians, generateStrings, generateUUIDs and generateBlobs.
With the JSON interface you can even...
...generate digitally signed random data, such that you can prove it really came from RANDOM.ORG (authenticity) and that your application has not tampered with it (integrity). This is useful if you want your application to implement non-repudiation.
Note that they use a quota system. This is based on IP:
RANDOM.ORG uses a simple quota system to make sure nobody hogs all the random numbers produced by the generator.