If you've relied on carrier coverage maps to decide who gets your business, you know that they're sometimes sketchy. A good connection on the map could still mean lousy service in your neighborhood, for instance. T-Mobile thinks it has a better solution: it just launched a crowdsourced coverage map. Instead of simply predicting the quality you're likely to get, the map draws on usage data (including customer reports and speed tests) to tell you what connections you can realistically expect. The maps are also updated twice a month, so you won't have to trust that months-old information is still accurate.