1. You might be able to get rid of the searchCriteria member by using inline anonymous delegates, like this:

public Accounts FindAccounts(string criteria)
{
Accounts foundAccounts = new Accounts(this.FindAll(delegate(Account account)
{
return MatchesFullNameOrPhone(account, criteria);
}
));
}

private bool MatchesFullNameOrPhone(Account account, string searchCriteria)
{
return account.Name.Contains(searchCriteria)
|| account.PhoneNumber.Contains(searchCriteria);
}

2. I’ve found a nice source-code formatter for blogger – you might want to use it (no offense intended :-)
http://formatmysourcecode.blogspot.com/

All the best,
– Avi