I've had a number of emails from customers asking where they can locate the DisableCertChk.Exe tool from for Windows Mobile 5. The Windows Mobile 2003 version is at http://www.microsoft.com/downloads/details.aspx?FamilyID=D88753B8-8B3A-4F1D-8E94-530A67614DF1&displaylang=en and is used to allow users with Windows Mobile devices to connect to Exchange servers without verifying the root certificate authority against the certificate trust list on the device. The device still uses SSL to connect to Exchange, but the Exchange Certificate check allows certificates from un-trusted certificate authorities to be used without generating errors.
Unfortunately I'm not aware of a version for Windows Mobile 5 however in the meantime - you can get certificates for $149 for a year from Geotrust Europe (http://www.geotrusteurope.com/quickssl/index.htm) and that price reduces if you buy multiple years.
If this is just a short term trial look at something like the Verisign free trial (http://www.verisign.co.uk/products-services/security-services/ssl/buy-ssl-certificates/free-trial/index.html )I'll post here if I do find one :)
Final point - The DisableCertChk.exe tool should be used only for testing purposes. Do not use this tool in your normal production environment.