Microsoft have a project on CodePlex
to fully enable JavaScript Intellisense for the Virtual Earth Map Control inside of Visual Studio 2008. Which you can find here.
This makes working with VE really easy.
I have noticed a few people (on forums etc) wishing for JavaScript intellisense for Google Maps. so I have created a js file that contains the information to enable this.
You can download this file here.
If you don't know what to do with this file check out Scott Gu's Blog on VS 2008 JavaScript Intellisense.
The basics is to place the js file in you
JavaScript folder and reference the file like so:
/// <reference path="googlemaps-intellisense.js" />
Please note that the js file contains NO functional Google Maps code, so you will still need to setup all the necessary links to the Google Maps API.
The Google Maps API is huge and sadly I have not been able to add every single Mapping object, but all the main ones are there.
If I get enough interest in this intellisense file I will keep developing (adding to) it. Let me know what you think and what you want to see in the next version.
Hope this helps.