(cjvitek is back with a review of Units ($.99 at the iTunes Store), a straightforward unit conversion app. It's currently sitting pretty at #4 on the bestseller list, but does it belong? Read on to find out!)
On my old Treo, I had a great conversion program which I used frequently. When I switched to the iPhone 3G, I was hoping to find a similar program. The best I have found so far is "Units".
Units is a conversion program that allows you to convert currencies, length, area, temperature, energy units, volume, time, speed, and weight. It has a simple, straightforward interface. First you select the mode you want to convert (say, currency), then the "from" units, then the "to" units. You select these options be repeatedly tapping on the "mode", "from", and "to" buttons until you get the selection you want. Then, using the calculator style interface, you type in the number you want converted. While I haven't used the currency converter yet, the currency values are updated daily (automatically) or you can update them yourself manually.