Methods and devices for networked applications are disclosed. In one embodiment, a device instructs a proxy server to receive traffic inbound for the device, and to notify the device when such traffic arrives. The device can then sleep, except for a notification channel that listens for a wakeup message from the proxy server. The proxy server detects traffic inbound for proxied devices, caches the data from that traffic, and issues notification messages to the proxied devices to cause those devices to download the cached data. One use for such a system is in instant messaging, as it allows a subscriber to place a battery-powered computing device in sleep mode while still advertising a continuous presence to her messaging buddies.