The HTC Excalibur (HTC S620) is a smartphone model manufactured by High Tech Computer beginning in 2006. It is rebranded and sold as the O2 Xda Cosmo, the T-Mobile Dash, the HTC S621 for Rogers Wireless in Canada, the HTC S621 for Suncom Wireless in the lower-eastern United States, the BT ToGo (as part of the BT Total Broadband Anywhere package), and the Dopod C720W.