Please remember that fees for most filings with US Citizenship and Immigration Services (USCIS) will increase on 23 November 2010. Applications submitted with incorrect fees will be rejected, and such a rejection could result in the applicant falling out of status in the USA, so it’s important to be sure to file with the correct fee.
The USCIS statement about the increased fees, and the list of the increased fees, can be found here. –jcf