During the late 1990s dot-com boom, Silicon Valley lawyers were so keen to latch on to up-and-coming technology companies that they often waived their usual legal fees in exchange for small ownership stakes in the start-ups. When many of those companies went bust, lawyers most likely wished they had asked for money instead.Amid Silicon Valley's latest tech boom, law firms once again are taking equity stakes in start-ups--but this time they generally aren't waiving their fees and instead are often deferring them or charging special rates.