A ubiquitous city is where everything is interconnected with everything else, where information is instantaneously shared. In a U-city, people can access a variety of web data in any kind of form by using small-screened mobile devices. In this paper we propose an approach which provides web information in either auditory or visual presentation by creating additional VoiceXML documents from existing HTML documents. This approach obtains the benefit that users are able to get web information by viewing and by hearing at the same time via mobile devices. We explain algorithms for the efficient conversions to multimodal web pages and a system design based on these algorithms. Keywords Multimodal Web Information, Web Document Conversion, HTML, VoiceXML, Mobile Services in a U-City