LG Lucid doesn't recognize SD card as extra memory when dealing with photos Possible Duplicate:
  How can I deal with “Low on Space” messages on my HTC Incredible?  




I have an LG Lucid, and recently (more or less) learned how to put files (music, etc.) on it from my Mac.

My question is: Why does my phone constantly think the memory is full when I'm looking through or taking photos? A little box pops up and tells me to delete files to make room. It still saves the photos I take, but it doesn't save the screenshots. 

Does anyone know how to fix this?
There are multiple things you need to adjust -- let's step through them one by one:
Camera
Unfortunately not on all devices / Android versions, but some camera apps let the user configure where to store the photos (phone memory or sd). Check if your camera app supports this. If so, set it to sd (or &quot;external&quot; -- all but phone ;). If not, you might want to check the playstore for alternative camera apps offering this feature. Videos, photos, and music files are most likely the largest files on your device -- so keeping those away from your precious internal storage will reduce the possibility / frequency dropping into this problem.
Make room
As you said you get the &quot;Memory low&quot; or &quot;Insufficient storage&quot; errors, free space on your internal device memory (phone memory) most likely dropped below 25 MB. So as advised by that popup, you should make room. I'm not going into details on this, as this is already explained here multiple times. Check e.g. the following questions:

What can I do to manage my phone's internal storage?
How can I free up more space on my Android phone?
How can I deal with “Low on Space” messages?

Additionally, check out the list of most frequent questions tagged &quot;internal-storage&quot;, which will list you even more useful questions (with answers, of course).
Screenshots
Once you've sorted out above two things, this problem has solved magically as a side-effect :)