Both Yahoo and Google have created landing pages for their mobile offerings at http://mobile.google.com and http://mobile.yahoo.com.
As interest in mobile banking picks up, financial institutions should create a mobile service page under the URL http://mobile.yourbank.com.
For example, Singapore's OCBC Bank has a WAP site at http://mobile.ocbc.com. that has links to basic info and the downloadable application used for True Mobile Banking (see mobile phone image right).
The bank also has a mobile information page on its regular website (here) that provides information about its mobile services. Currently, there is nothing like it in the U.S., but Citibank/mFoundry appear to be on the verge of a launch in early 2007 (see OCBC banner above and screenshot of complete webpage below, click to enlarge).
Even if you don't have a WAP site or other mobile services, you should at least provide information on text-based alerts which work well for most mobile devices.
In a test of the 20 largest U.S. retail banks, only Fifth Third has a URL with the word "mobile" <http://mobile.53.com>. However, unlike OCBC, Fifth Third's mobile URL has not been optimized for mobile access (WAP), nor does it contain any info on mobile services. Either Fifth Third is about to launch a mobile initiative, or they just have very thorough Web programmers.