Besides Military service, a leave of absence from your business can be a way to delay payment on your loan taken from a solo 401k.
As you know, a default on your 401k loan can cause the loan balance to be taxable and subject to a 10% penalty. Put a leave of absence policy in place to give yourself more flexibility.
You might even use this technique to move the tax liability to 2009 rather than taking the hit in 2008.
The rest of the story is that you will need to recast the loan after return from the leave of absence. You cannot walk away from the loan or the interest owed – just delay it.