21. A system for automatically constructing wrappers across a plurality of domains, the system comprising: a memory; and a processor coupled to the memory, the processor configured to: identify a first target string that is consistent or near-consistent across a plurality of domains, each of the plurality of domains comprising one or more documents common to at least one other of the plurality of domains; create a first wrapper for a first domain from the first target string; extract additional target information based on the first target string from one or more documents in the first domain; search domains in the plurality of domains other than the first domain to determine if any of the other domains comprises at least one document having at least one portion of the additional target information; and create a second wrapper for at least one of the other domains in the plurality of domains based on the extracted additional target information.
21. A system for automatically constructing wrappers across a plurality of domains, the system comprising: a memory; and a processor coupled to the memory, the processor configured to: identify a first target string that is consistent or near-consistent across a plurality of domains, each of the plurality of domains comprising one or more documents common to at least one other of the plurality of domains; create a first wrapper for a first domain from the first target string; extract additional target information based on the first target string from one or more documents in the first domain; search domains in the plurality of domains other than the first domain to determine if any of the other domains comprises at least one document having at least one portion of the additional target information; and create a second wrapper for at least one of the other domains in the plurality of domains based on the extracted additional target information. 24. The system of claim 21 , wherein the processor is further configured to: extract additional target information from one or more documents in the first domain by applying the first wrapper to the documents in the first domain.