Keep in mind for your laptop, for example, you shouldn't need a power converter, just a plug adapter. Your laptop's power converter should already do the conversion.
For example, my Dell power adapter for my laptop says "Input: 100-240v ~ 50-60hz" It will accept 220/240v input @ 50Hz as long as my plug fits into the socket. As already mentioned, you can get the universal plug adapters at Radio Shack, Fry's, or any electronics store.
Other items might need a power converter - such as my Nintendo DS I believe (can't find the plug at the moment) doesn't do more than 110v input, so I'd need a power adapter rather than just the plug. You can check each of the power converts / power adapters to any electronics you will be bringing to see if you only need plugs, or the power adapters also
BTW, I just wanted to mention that I'm pretty new to Chnlove and all of this information and on-going communication is a humongous help. Thanks guys!