SFDC visualforce page get url parameters

{!$CurrentPage.parameters.RecordType} — get RecordType

$CurrentPage.parameters.parameter_name

<apex:page standardController="Account">
    <apex:pageBlock title="Hello {!$User.FirstName}!">
        You are displaying values from the {!account.name} account and a separate contact
        that is specified by a query string parameter.
    </apex:pageBlock>
    <apex:pageBlock title="Contacts">
        <apex:dataTable value="{!account.Contacts}" var="contact" cellPadding="4" border="1">
              <apex:column>
               <apex:facet name="header">Name</apex:facet>
                {!contact.Name}
              </apex:column>
              <apex:column>
               <apex:facet name="header">Phone</apex:facet>
              {!contact.Phone}
              </apex:column>
        </apex:dataTable>
    </apex:pageBlock>
    <apex:detail subject="{!$CurrentPage.parameters.cid}" relatedList="false" title="false"/> 
</apex:page>

http://www.salesforce.com/us/developer/docs/pages/Content/pages_quick_start_query_params_getting.htm