1.打电话

可以自己写界面，在button的单击事件中添加如下代码即可：

   Intent intent = new Intent();
   intent.setAction("android.intent.action.CALL");
   intent.setData(Uri.parse("tel:"+ mobile));//mobile为你要拨打的电话号码，模拟器中为模拟器编号也可
   startActivity(intent);

需要添加打电话权限：

<uses-permission android:name="android.permission.CALL_PHONE" />

2.发短信

和打电话差不多，在button的单击事件中添加如下代码：

    SmsManager smsManager = SmsManager.getDefault();
    ArrayList<String> texts = smsManager.divideMessage(content);//拆分短信,短信字数太多了的时候要分几次发
    for(String text : texts){
     smsManager.sendTextMessage(mobile, null, text, null, null);//发送短信,mobile是对方手机号
    }

对应发短信权限：

<uses-permissionandroid:name="android.permission.SEND_SMS" />

下面是转载来的其他的一些Intent用法实例

显示网页
    Uri uri = Uri.parse("http://google.com");  
    Intent it = new Intent(Intent.ACTION_VIEW, uri);  
    startActivity(it);

显示地图
    Uri uri = Uri.parse("geo:38.899533,-77.036476");  
    Intent it = new Intent(Intent.ACTION_VIEW, uri);   
    startActivity(it);   
    //其他 geo URI 範例  
    //geo:latitude,longitude  
    //geo:latitude,longitude?z=zoom  
    //geo:0,0?q=my+street+address  
    //geo:0,0?q=business+near+city  
    //google.streetview:cbll=lat,lng&cbp=1,yaw,,pitch,zoom&mz=mapZoom

路径规划
    Uri uri = Uri.parse("http://maps.google.com/maps?f=d&saddr=startLat%20startLng&daddr=endLat%20endLng&hl=en");  
    Intent it = new Intent(Intent.ACTION_VIEW, uri);  
    startActivity(it);  
    //where startLat, startLng, endLat, endLng are a long with 6 decimals like: 50.123456

打电话
    //叫出拨号程序 
    Uri uri = Uri.parse("tel:0800000123");  
    Intent it = new Intent(Intent.ACTION_DIAL, uri);  
    startActivity(it);  
    //直接打电话出去  
    Uri uri = Uri.parse("tel:0800000123");  
    Intent it = new Intent(Intent.ACTION_CALL, uri);  
    startActivity(it);  
    //用這個，要在 AndroidManifest.xml 中，加上  
    //<uses-permission id="android.permission.CALL_PHONE" />

传送SMS/MMS
    //调用短信程序 
    Intent it = new Intent(Intent.ACTION_VIEW, uri);  
    it.putExtra("sms_body", "The SMS text");   
    it.setType("vnd.android-dir/mms-sms");  
    startActivity(it); 
    //传送消息 
    Uri uri = Uri.parse("smsto://0800000123");  
    Intent it = new Intent(Intent.ACTION_SENDTO, uri);  
    it.putExtra("sms_body", "The SMS text");  
    startActivity(it); 
    //传送 MMS  
    Uri uri = Uri.parse("content://media/external/images/media/23");  
    Intent it = new Intent(Intent.ACTION_SEND);   
    it.putExtra("sms_body", "some text");   
    it.putExtra(Intent.EXTRA_STREAM, uri);  
    it.setType("image/png");   
    startActivity(it);

传送 Email
    Uri uri = Uri.parse("mailto:xxx@abc.com");  
    Intent it = new Intent(Intent.ACTION_SENDTO, uri);  
    startActivity(it);

    Intent it = new Intent(Intent.ACTION_SEND);  
    it.putExtra(Intent.EXTRA_EMAIL, "me@abc.com");  
    it.putExtra(Intent.EXTRA_TEXT, "The email body text");  
    it.setType("text/plain");  
    startActivity(Intent.createChooser(it, "Choose Email Client"));

    Intent it=new Intent(Intent.ACTION_SEND);    
    String[] tos={"me@abc.com"};    
    String[] ccs={"you@abc.com"};    
    it.putExtra(Intent.EXTRA_EMAIL, tos);    
    it.putExtra(Intent.EXTRA_CC, ccs);    
    it.putExtra(Intent.EXTRA_TEXT, "The email body text");    
    it.putExtra(Intent.EXTRA_SUBJECT, "The email subject text");    
    it.setType("message/rfc822");    
    startActivity(Intent.createChooser(it, "Choose Email Client"));

    //传送附件
    Intent it = new Intent(Intent.ACTION_SEND);  
    it.putExtra(Intent.EXTRA_SUBJECT, "The email subject text");  
    it.putExtra(Intent.EXTRA_STREAM, "file:///sdcard/mysong.mp3");  
    sendIntent.setType("audio/mp3");  
    startActivity(Intent.createChooser(it, "Choose Email Client"));

播放多媒体
       Uri uri = Uri.parse("file:///sdcard/song.mp3");  
       Intent it = new Intent(Intent.ACTION_VIEW, uri);  
       it.setType("audio/mp3");  
       startActivity(it); 
       Uri uri = Uri.withAppendedPath(MediaStore.Audio.Media.INTERNAL_CONTENT_URI, "1");  
       Intent it = new Intent(Intent.ACTION_VIEW, uri);  
       startActivity(it);

Market 相关
        //寻找某个应用 
        Uri uri = Uri.parse("market://search?q=pname:pkg_name"); 
        Intent it = new Intent(Intent.ACTION_VIEW, uri);  
        startActivity(it);  
        //where pkg_name is the full package path for an application 
        //显示某个应用的相关信息 
        Uri uri = Uri.parse("market://details?id=app_id");  
        Intent it = new Intent(Intent.ACTION_VIEW, uri); 
        startActivity(it);  
        //where app_id is the application ID, find the ID   
        //by clicking on your application on Market home   
        //page, and notice the ID from the address bar

Uninstall 应用程序
        Uri uri = Uri.fromParts("package", strPackageName, null); 
        Intent it = new Intent(Intent.ACTION_DELETE, uri);   
        startActivity(it);