If you're technically-oriented and eager for a challenge, explore Googling "AOL Linux" if you also own a USB modem, and if you're willing to seriously explore this installation process, at your own risk.
AOL Instant Messanger
Similarly, for AOL Instant Messenger, we regret it's similarly not supported by OLPC. While there are probably ways to install it (in Terminal mode, using your XO laptop's underlying Red Hat/Fedora operating system) you will need to be technically very savvy, and research others' past Linux work here. Using meebo is a web-based alternative.