The four dominate post-paid carriers each offer a discount to UPSers. Some allow the discount to be applied to an existing account, others allow it for new accounts only. Some apply the discount to the entire bill, some apply it to the primary line charges only.
If you live in a Metro PCS market, they offer unlimited talk/text/data for $40 including taxes. Occasionally they offer it for $30. They sell Metro PCS-branded Galaxies, but you can bring your own or even your iPhone if you're off contract. Without question, one of the best bargains available today (across any industry). Note that MetroPCS has acquired T-Mobile and is in the process of merging (but keeping the T-Mobile name).