If your firm falls in that special place were you don't use a full accounting platform here are some great online services that help you get your invoices out and ecurage your customers to pay. Kudos to Alyssa Gregory at sitepoint.com for putting this list together. Go here for descriptions on all the invoicing tools.

Bill4Time BillMyClients Billing Manager Billing Orchard Blinksale Cashboard Easy Bill Free Agent Freshbooks The Invoice Machine

Invoice Place Invoices Made Easy Invotrak Less Accounting LiteAccounting PayPal Simply Bill Simply Invoices Time 59 Winkbill

Xero Zoho Invoice