<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" 
                  android:key="first_preferencescreen">  
  <EditTextPreference android:key="openid" 
                      android:title="OpenID URL" />
  <PreferenceScreen android:key="second_preferencescreen" 
                    android:title="Position Frequency" >
    <EditTextPreference android:key="record frequency"
                        android:title="Fixes Per Hour"
                        android:digits="0123456789" />
    <EditTextPreference android:key="transmission frequency"
                        android:title="Transmissions Per Hour"
                        android:digits="0123456789" />
  </PreferenceScreen>
  <!-- <CheckBoxPreference android:key="wifi enabled" 
                      android:title="Use WiFi Location" /> -->  
       
                                           
</PreferenceScreen>

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" 
                  android:key="first_preferencescreen">  
  <EditTextPreference android:key="openid" 
                      android:title="OpenID URL" />
  <ListPreference android:key="record frequency"
                  android:title="Position Frequency"
                  android:entries="@+array/time_frequency"
                  android:entryValues="@+array/time_frequency_values" />
  <EditTextPreference android:key="transmission frequency"
                      android:title="Transmissions Frequency"
                      android:entries="@+array/time_frequency"
                      android:entryValues="@+array/time_frequency_values" />
  <!-- <CheckBoxPreference android:key="wifi enabled" 
                      android:title="Use WiFi Location" /> -->  
</PreferenceScreen>

Use a pulldown list instead of a text field
Use a pulldown list instead of a text field
