I carry adapters specific to the area I'm visiting. They're inexpensive and lightweight. I think they make multi-purpose adapters, but I prefer the simpler ones that just do one thing.
For Tanzania, it looks like you need type G or D. You might want to take one of each - I've found that in countries with more than one type, it's hard to know which type a particular lodging will use.
Also be aware that you'll need converters since they use 230 V and the US uses 120. Some of your devices already have converters.
On our last trip, we took a big 10 USB hub with integrated converter, along with an adapter. It was enough for all the charging for 5 people - all 10 or so devices we felt necessary to bring with us :). We needed a separate adapter for the device (laptop) that didn't charge via USB.
@nteaver Hey Nick, Tanzania sounds like an awesome trip!
REI does carry a small selection of both travel adapters and converters. Here's a great article with lots of details on travel & electricity! A travel adapter allows you to plug your device directly into the wall, which is the first step in powering your devices.
Adding a travel converter takes that power and converts the voltage so you don't overwhelm the connection, potentially damaging your electronics. Note that many devices can run on dual voltage, so you will only need a converter if your devices don't have dual-voltage capability.