1. A computer-implemented method of realizing an associative memory capable of storing a set of documents and retrieving one or more of said stored documents similar to an inputted query document, said method comprising: coding each of said stored document or a part of it through a corresponding feature vector consisting of a series of bits which respectively code for the presence or absence of certain features in said document; arranging said feature vectors in a matrix; generating a query feature vector based on the query document and according to the rules used for generating the feature vectors corresponding to the stored documents such that the query vector corresponds in its length to the width of the matrix; for those columns of the matrix where the query vector indicates the presence of a feature, bitwise performing one or more of preferably hardware supported logical operations between the columns of the matrix to obtain one or more additional result columns coding for a similarity measure between the query and parts or the whole of the stored documents; and said method further comprising one or a combination of the following: retrieval of one or more stored ducuments based on the obtained similarity measure; and or storing a representation of a document though its feature vector into the above matrix.