For those saying that the answer of @kuester2000 does not work, please be aware that HTTP requests, first try to find the host IP with a DNS request and then makes the actual HTTP request to the server, so you may also need to set a timeout for the DNS request. 
If your code worked without the timeout for the DNS request it's because you are able to reach a DNS server or you are hitting the Android DNS cache. By the way you can clear this cache by restarting the device.
This code extends the original answer to include a manual DNS lookup with a custom timeout:
//Our objective
String sURL = "http://www.google.com/";
int DNSTimeout = 1000;
int HTTPTimeout = 2000;
//Get the IP of the Host
URL url= null;
try {
     url = ResolveHostIP(sURL,DNSTimeout);
} catch (MalformedURLException e) {
    Log.d("INFO",e.getMessage());
}
if(url==null){
    //the DNS lookup timed out or failed.
}
//Build the request parameters
HttpParams params = new BasicHttpParams();
HttpConnectionParams.setConnectionTimeout(params, HTTPTimeout);
HttpConnectionParams.setSoTimeout(params, HTTPTimeout);
DefaultHttpClient client = new DefaultHttpClient(params);
HttpResponse httpResponse;
String text;
try {
    //Execute the request (here it blocks the execution until finished or a timeout)
    httpResponse = client.execute(new HttpGet(url.toString()));
} catch (IOException e) {
    //If you hit this probably the connection timed out
    Log.d("INFO",e.getMessage());
}
//If you get here everything went OK so check response code, body or whatever
Used method:
//Run the DNS lookup manually to be able to time it out.
public static URL ResolveHostIP (String sURL, int timeout) throws MalformedURLException {
    URL url= new URL(sURL);
    //Resolve the host IP on a new thread
    DNSResolver dnsRes = new DNSResolver(url.getHost());
    Thread t = new Thread(dnsRes);
    t.start();
    //Join the thread for some time
    try {
        t.join(timeout);
    } catch (InterruptedException e) {
        Log.d("DEBUG", "DNS lookup interrupted");
        return null;
    }
    //get the IP of the host
    InetAddress inetAddr = dnsRes.get();
    if(inetAddr==null) {
        Log.d("DEBUG", "DNS timed out.");
        return null;
    }
    //rebuild the URL with the IP and return it
    Log.d("DEBUG", "DNS solved.");
    return new URL(url.getProtocol(),inetAddr.getHostAddress(),url.getPort(),url.getFile());
}   
This class is from this blog post. Go and check the remarks if you will use it.
public static class DNSResolver implements Runnable {
    private String domain;
    private InetAddress inetAddr;
    public DNSResolver(String domain) {
        this.domain = domain;
    }
    public void run() {
        try {
            InetAddress addr = InetAddress.getByName(domain);
            set(addr);
        } catch (UnknownHostException e) {
        }
    }
    public synchronized void set(InetAddress inetAddr) {
        this.inetAddr = inetAddr;
    }
    public synchronized InetAddress get() {
        return inetAddr;
    }
}