How do you handle (budget, monitor, program manage) the non-stop technology race

When many of us grew up, it was the arms' race or the space race. Today it's the technology race. It seems that every day the technology we bought or leased is no longer cutting edge; in many cases it is irrelevant. Or, because the technology isn't up to snuff, be it latest greatest or more likely it isn't fully implemented or properly implemented, our companies suffer and so do our bottom lines. An interesting article in the May CFO magazine "Seed Trap" talks about this phenomenon targeting obviously financial type systems. But the issue is just about finance systems; its about all systems. The anthesis to issue is when is or at what point is the latest and greatest technology enough; is that incremental increase in power, speed, functionality worth the cost? Especially if our employees are not taking advantage of the systems currently in place. How do you, the executive weigh these factors and find the right mix of functionality, cost, training and productivity?