With the proliferation of Web services, it is becoming increasingly important to support the users in selecting the most appropriate compositions of services for a task. We propose a new service discovery and selection framework that utilises the concept of task memories and a social network of task memories. A task memory captures the service composition history and their meta-data such as associated context and user rating. A network of task memories is formed to realise an effective task memory sharing platform among the users. The service selection process recommends combinations of services that are most appropriate in a given context by consulting the network of task memories. The continuous updates of the task memories over time will result in more fine-tuned recommendations for composite services.