Exactly the same as I was told today (thanks to those who posted the telephone numbers for UPS/Customs) Spoke with a very helpful chap @ UPS who explained that they work on behalf of Parcefarce for international packages - dealing with the customs side.
Mine was sent Express 24 from USPS - below is the timeline as per the parcelforce website:
Date Time Location Tracking Event
25-04-2010 19:28 International Hub AWAITING CUSTOMS CHARGING
25-04-2010 19:28 International Hub AWAITING CUSTOMS CHARGES
25-04-2010 19:24 International Hub Arrived in destination country
16-04-2010 11:28 Delivery Agent - CHICAGO Left origin country
16-04-2010 08:12 Delivery Agent - CHICAGO Arrived at Outward OE
15-04-2010 10:42 Delivery Agent - UNITED STATES AMERICA Collected from customer
Thankfully WFH today - so could spend quite a bit of time re-dialling trying to get through.
So currently it's been sat with UPS for the last 2 days. Hopefully I'll get it before the weekend ........