At least up to Illustrator 13, there is a trick or rather a lousy hack that involves the Snap to Grid command and its talent to temporarily disable any Smart Guides functionality. The following has to be prepared in case you're going to execute the hack as an action:
1. In the Actions Palette, create a new Action set. Call it 'Disable Smart Guides'.
2. Within the Action set, create a new action. Call it 'Disable Smart Guides', assign an F-key to the action, let's say F3, and hit Enter.
3. In the Actions Palette menu, select the Insert Menu Item command and go to View > Snap to Grid
4. Stop recording the action
5. Go to Edit > Preferences > Guides & Grid
6. In the Gridline Every text box, enter 0,01 mm. It's the minimum value you can set here.
7. In the Subdivisions text box, enter 1000, the max. value accepted here.
Now, take any document, turn on Smart Guides, make sure Snap to Grid is turned off, and start drawing a path. Hit F3 and continue drawing the path. Hit F3 again as soon as you need your Smart Guides again.
As you can see, after hitting F3 to enable Snap to Grid, the path will not be interrupted when placing the next point. And as you've got a kind of microscopic Grid settings, Snap to Grid has almost no influence on where the points are placed. In fact, it still snaps, but due to the absurd Grid settings it's rather negligible.
This palpable workaround was originally invented by a young lady located around Edmonton in Canada.
Wow, that is absolutely disgusting but it works. Brilliant. Thanks.
I wonder why it works for Snap to Grid, but I can't just do the same thing directly with Smart Guides..
It has to do with one snap function overriding the other.