As some have alluded to, the MS guidelines say:
Do not use a prefix for field names.
For example, do not use g_ or s_ to
distinguish static versus non-static
fields.
I happen to agree with this. prefixes make your code look ugly and waste space with inconsequential characters. Having said that, it is often common to use fields to back properties where both the field and the property would have the same name (with the private field being camel case and the property being pascal case). In VB, this doesn't work, since VB isn't case-sensitive. In this scenario, I recommend the use of a single _ prefix. No more, no less. It just looks cleaner, IMHO.
