Here's a great recipe for vanilla extract. This is one of my favorite DIY projects. You'll never use store-bought extract after you've made this! These make great gifts too!
I used Tahitian vanilla beans, which are readily available via the internet. I bought my bottle at World Market. Sorry for the poor quality of my picture, not sure why I couldn't get a clear picture.... my extract is low and I just haven't gotten around to getting more vodka.
vodka (any type will do)
1 vanilla bean per 1/3 cup of vodka
glass jar/bottle with lid
Split each lengthwise with sharp knife or scissors. Drop beans into the bottle and fill with vodka. That's it! Store in a cool dark place from 1 to 3 months, giving them a shake every once in a while. The extract will continue to get darker and more aromatic over time. As you use the extract, add more vodka. The beans won't go bad - the alcohol acts as a preservative.