Tips on optimizing cost on wireless data cards

Do you offer wireless data card (aka Aircards in US and 3G cards in Asia) as a subscription service for your users? Is it becoming a increasing indirect cost creep for your business leaders? Here are some ideas to curb this spend:

• Negotiate a deal with the vendor to allow unused data to be pooled for other cards and carried forward to the next month
• Work out a eligibility criteria based on cost-savings e.g. if a employee travels domestically for more than X number of nights per year and assuming that he/she pays the hotel a service fee to use the Internet broadband (if you are in countries like Japan, this is irrelevant because most hotels provide Internet broadband for free), then issuing a wireless data cards would be a cost-saving measure
• Pool the cards by depts or company level (depending on which is practically managable) so that the usage of the cards are maximized.

Other ideas are welcome