I've had an AMEX Business Gold Charge Account for 4 Years now. I've Maintained balances between $200 and $4000 monthly. I pay it off every month and GUESS WHAT?????
It doesn't show up and my credit report. Charge Accounts can work wonders for your score since you settle up on a monthly basis.
Only reason I don't sweat it is because i have a 780 Middle Credit Score.