KirstyK, it appears that Vlingo is pre-installed on the GalaxyS2. I did a quick search under 'uninstall vlingo voice talk' using Bing. This thread response might be of help http://blog.vlingo.com/voice-talk-intomobile/
If it doesn't, you could check out other search responses using wording more suitable to the problem.
All the best as I too hate 'things' talking to me!!