You can indent values in cells using EditGrid which free.
It provides with a whole range of Excel like functionality.
Cut-and-paste, sorting, charts,
auto-fill, cell border, number
formatting, cell formatting, import,
export, print, find, undo, redo,
freeze pane, text overflow, auto-fit
row/column size, word warp, cell
comments, 500+ functions ... You name
it, EditGrid has it.
EditGrid can import/export your
spreadsheets from/to many popular
spreadsheet file formats, including
Microsoft Excel (.xls), OpenDocument
(.ods), OpenOffice.org (.sxc), CSV
(.csv), and many others.
You can try out an online demo of EditGrid here