Android: If you downloaded the latest version of Chrome Beta for Android, you now have access to Google's data compression feature, which optimises website content so it loads faster and chews up less data. The feature isn't on by default, however, so here's how to turn it on.
In the omnibox, type in chrome://flags. Enable the first setting on that experimental features page, "Enable Data Compression Proxy". Google says its web accelerator has been shown to reduce data usage by 50 per cent, and in my brief tests visiting a few sites, I found that to be a close approximation. Even better, the Google Operating System blog points out that unlike Opera Mobile's Turbo feature, Chrome doesn't slow down your browsing, while saving almost the same amount of data.
To see how much data you've saved yourself, type in chrome://net-internals, then go to Bandwidth. After visiting a few sites in another tab, you can view those sweet optimisation stats. Just another reason to try the beta, in addition to the new password sync and autofill features.