24. A system for building a custom word list for use in text operations on an electronic device, comprising: a first data store for storing a collection of text items associated with a user of the electronic device; a scanning module configured to scan the collection of text items to identify words in the text items; a weighting module configured to assign a weighting to each identified word; a second data store for storing each identified word and its corresponding weighting; and a module configured to determine a source of each text item in the collection of text items; wherein the weighting module calculates the weighting for each identified word based on the source of the text item in which the word was identified.
26. The system of claim 24 , wherein the first data store comprises storage areas in a plurality of memory components.