If Google (Nasdaq: GOOG) didn't impress you with the Nexus One smartphone, maybe one of its newborn brethren will.

Sprint Nextel (NYSE: S) has introduced its first 4G-capable handset, and it's an ultra-modern Android model built by Nexus maker HTC. Both phones share the same software platform and a similar 1-gigahertz Qualcomm (Nasdaq: QCOM) SnapDragon processor, but the phone formerly known as the Supersonic -- now rechristened to the not-so-snappy moniker HTC EVO 4G -- blows its brother away in many ways.

Chief among them, of course, is the power to connect to high-speed 4G networks. In completely unrelated news, I'm sure, Sprint also picked today to announce seven new markets that will get 4G coverage through the Clearwire (Nasdaq: CLWR) WiMax network by the end of 2010, including metropolises like Los Angeles and Miami.

4G networking is much faster than the prevailing 3G standards, but devices making use of the technology are scarce. When the (gasping for air!) HTC EVO 4G phone (whew!) hits Sprint stores this summer, it will surely be followed by plenty of alternatives. Verizon (NYSE: VZ) and AT&T (NYSE: T) will join the 4G party in stages, using the competing LTE technology instead of WiMax.

Then there's the Samsung Galaxy S, also announced today. It sports a uniquely slim shape, the most advanced OLED screen seen so far, and reportedly a better touch-screen experience thanks to a rethinking of how the screen elements are put together. This one appears to be aimed at networks like AT&T Wireless and T-Mobile. The original Samsung Galaxy made me drool uncontrollably last year but never actually came to America. This time, it's even better and we've been promised an American release.

Forbes calls the Galaxy S "a revolutionary smart phone" that will be "Samsung's Apple (Nasdaq: AAPL) iPhone competitor." This one and the Supersonic/EVO 4G manage to put the Nexus One to shame and present a fresh challenge to the iPhone's dominance on American soil.

Should Apple be running scared of the Android invasion yet ? Discuss in the comments below.

Fool contributor Anders Bylund owns shares in Google, but he holds no other position in any of the companies discussed here. Sprint Nextel is a Motley Fool Inside Value recommendation. Google is a Motley Fool Rule Breakers choice. Apple is a Motley Fool Stock Advisor recommendation. Try any of our Foolish newsletters today, free for 30 days. You can check out Anders' holdings and a concise bio if you like, and The Motley Fool is investors writing for investors.