In 1998 after having heard about how wonderful Esperanto was, and particular how easy it was to learn, I decided to find out if these claims were true. I started learning it with Teach Yourself Esperanto and later found the lernu! website, which has some very good courses, including a whole novel in Esperanto, Gerda malaperis! (Gerda Vanished!), by Claude Piron, which, has also been made into a film.
Esperanto is indeed quite easy to learn, especially if you already know English and/or a Romance, Germanic or Slavic language. Some aspects of the language, such as the accusative case and some of the sounds, and might be tricky for some, but aren't nearly as challenging as the grammar and sounds of other languages.
I've learnt enough Esperanto to be able to understand and read it, and can speak and write it quite well. I use it at the polyglot events, and also practice it with a friend on Skype fairly regularly.
Welsh, French, German, Italian, Icelandic, Japanese, Portuguese, Mandarin, Cantonese, Taiwanese, Korean, Scottish Gaelic, Spanish, Esperanto, Hungarian, Turkish, Arabic, Czech, Irish (Gaelic), Latin, Manx (Gaelic), Russian, Urdu, British Sign Language (BSL), Hindi, Breton