1. A method of aggregating web services in generating a user interface for a computing device, the method comprising: receiving at least one web service description, wherein said at least one web service description comprises a plurality of web service description elements that define a web service interface to each of a plurality of web services; processing said at least one web service description to identify inputs to and outputs from associated web services; generating one or more user interfaces through which input data is obtainable and output data is displayable; providing said one or more user interfaces, wherein in use, at least a subset of said plurality of web services is invoked using input data obtained through said one or more user interfaces, and wherein output data is displayed through said one or more user interfaces from said at least a subset of said plurality of web services; monitoring said input data obtained and said output data displayed during use of said one or more user interfaces to identify patterns in said input data and said output data that suggest that an input to a first web service of said plurality of web services is obtainable from output of a second web service of said plurality of web services; and generating a new user interface for said computing device if said patterns are identified, wherein in use, the first web service is automatically invoked using output data from the second web service when the second web service is invoked through said new user interface.