I wanted to load Navizon onto my phone to give me GPS type capability even when I don't have a GPS using wireless access point and Mobile Phone Cell triangulation (and it pays me $$'s when I feed it information), however there was an issue with the locked down nature of my E650.  Upon searching the web, this page was the one that had the real answer - note you need to sign up to the site to be able to download the magic program:

xda-developers - View Single Post - Application unlock for HTC Monet (Virgin Lobster 700tv)

Application unlock for HTC Monet (Virgin Lobster 700tv)

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Been trying everything on the Internet and managed to make some headway with Monet (Virgin Lobster 700tv) unlock (this might work for Meteor/C700 as well).
1. Firstly you need to get rid of the 'registry security policy' lock.
Download cert install sp.zip:
[see attachment]
a. copy "SP_AllowCertificateInstall.cab" to the root of Monet memory or card
b. Use file explorer on monet to navigate to file. Click to run. Should run ok.
c. Unzip "SDA_ApplicationUnlock.zip" on PC and run "SDA_ApplicationUnlock.exe" whilst Monet is connected via activesync
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ttfn

David