I've made regular bar soap before. In fact, I found (and use) a very simple recipe that I included in my book (p. 121 - for those with a copy of the book). It has three ingredients (four if you add an essential oil) - lye, lard, and distilled water - and makes a couple of small bars. I like to add lavender essential oil, and since I have a bunch of dried lavender, I'll also had a tablespoon of that for texture, color and scent.
While I love the bar soap, there's something to be said for liquid soap. It works better as a laundry soap, as a dish soap, and in general in most cleaning applications. While weirdos, like me, use bar soap all over in the shower, there's a reason (some) people prefer the shampoo in the plastic bottles.
Northwest Edible Life published a great article recently on making liquid Castille soap. What's great about this is that I lurve Dr. Bonner's liquid soap, and I use it for everything from washing to cleaning my toilets ... but it's pretty pricey for scrubbing the john. I haven't priced out the cost of this DIY Castille soap, but from a cursory glance at the ingredients, it looks like I probably have everything I need.
Guess I'm going to be a busy girl over the next few weeks :).