Do you have Outlook? You can sync the contacts with that.
Or, if you have a Google account, you can set up Google Sync on the iPhone (uses Exchange) & sync your contacts to Google Contacts.
EDIT: Sorry, seem to have ignored the whole "copy to SIM" side of what you wanted! Prob. not much help then

. Although if you're wanting to copy them to the SIM so they can later be copied from the SIM to a different phone altogether, then perhaps sync'ing to Outlook or Google could help as an intermediate step instead of the SIM (iPhone > Outlook/Google > new phone, instead of iPhone > SIM > new phone).