Supplying technical information is a great start:
Crystal version
Database/connectivity used
Example data
Expected output
Memo fields are limited in different versions of Crystal, so your post will likely net more posts until you take the time to state your environment and intent.
If you want to have all memo fields concatenated (using terms like join will probably confuse people), here's one approach:
Group Header Formula:
whileprintingrecords;
stringvar MyMemo:=""
Details formula:
whileprintingrecords;
stringvar MyMemo:=MyMemo & {table.memo}
Group Footer Formula: // used to display the data
whileprintingrecords;
stringvar MyMemo
Again, you may receive errors depending upon your version of Crystal, so please take the time to post technical information.
-k